diff --git a/README.md b/README.md
index 566bcd53..8843d205 100644
--- a/README.md
+++ b/README.md
@@ -117,7 +117,7 @@ irm https://cdn.link-ai.tech/code/cow/run.ps1 | iex
 
 项目支持国内外主流厂商的模型接口，可选模型及配置说明参考：[模型说明](#模型说明)。
 
-> 注：Agent 模式下推荐使用以下模型，可根据效果及成本综合选择：deepseek-v4-flash、MiniMax-M2.7、glm-5.1、kimi-k2.6、qwen3.5-plus、claude-sonnet-4-6、gemini-3.1-pro-preview、gpt-5.4、gpt-5.4-mini、ernie-5.0
+> 注：Agent 模式下推荐使用以下模型，可根据效果及成本综合选择：deepseek-v4-flash、MiniMax-M2.7、glm-5.1、kimi-k2.6、qwen3.5-plus、claude-sonnet-4-6、gemini-3.1-pro-preview、gpt-5.4、gpt-5.4-mini、ernie-5.1
 
 同时支持使用 **LinkAI 平台** 接口，支持上述全部模型，并支持知识库、工作流、插件等 Agent 技能，参考 [接口文档](https://docs.link-ai.tech/platform/api)。
 
@@ -605,13 +605,13 @@ API Key 创建：在 [控制台](https://aistudio.google.com/app/apikey?hl=zh-cn
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "qianfan_api_key": "",
   "qianfan_api_base": "https://qianfan.baidubce.com/v2"
 }
 ```
 
- - `model`: 默认推荐填写 `ernie-5.0`（多模态，可直接识图），也可填写 `ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k`；当主模型为纯文本 ERNIE 时，Vision 工具会自动 fallback 到 `ernie-4.5-turbo-vl`
+ - `model`: 默认推荐填写 `ernie-5.1`（多模态，可直接识图），也可填写 `ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k`；当主模型为纯文本 ERNIE 时，Vision 工具会自动 fallback 到 `ernie-4.5-turbo-vl`
  - `qianfan_api_key`: 百度千帆 API Key，通常以 `bce-v3/` 开头，可在百度智能云控制台创建
  - `qianfan_api_base`: 可选，默认为 `https://qianfan.baidubce.com/v2`
 
@@ -619,7 +619,7 @@ API Key 创建：在 [控制台](https://aistudio.google.com/app/apikey?hl=zh-cn
 ```json
 {
   "bot_type": "openai",
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "open_ai_api_base": "https://qianfan.baidubce.com/v2",
   "open_ai_api_key": ""
 }
diff --git a/channel/web/web_channel.py b/channel/web/web_channel.py
index 6823c02d..02b2a862 100644
--- a/channel/web/web_channel.py
+++ b/channel/web/web_channel.py
@@ -780,7 +780,7 @@ class ConfigHandler:
         const.QWEN36_PLUS, const.QWEN35_PLUS, const.QWEN3_MAX,
         const.DOUBAO_SEED_2_PRO, const.DOUBAO_SEED_2_CODE,
         const.KIMI_K2_6, const.KIMI_K2_5, const.KIMI_K2,
-        const.ERNIE_5, const.ERNIE_X1_1, const.ERNIE_45_TURBO_128K, const.ERNIE_45_TURBO_32K,
+        const.ERNIE_5_1, const.ERNIE_5, const.ERNIE_X1_1, const.ERNIE_45_TURBO_128K, const.ERNIE_45_TURBO_32K,
     ]
 
     # Generic placeholder hints surfaced in the web console. We deliberately
@@ -873,7 +873,7 @@ class ConfigHandler:
             "api_base_key": "qianfan_api_base",
             "api_base_default": "https://qianfan.baidubce.com/v2",
             "api_base_placeholder": _PLACEHOLDER_QIANFAN,
-            "models": [const.ERNIE_5, const.ERNIE_X1_1, const.ERNIE_45_TURBO_128K, const.ERNIE_45_TURBO_32K],
+            "models": [const.ERNIE_5_1, const.ERNIE_5, const.ERNIE_X1_1, const.ERNIE_45_TURBO_128K, const.ERNIE_45_TURBO_32K],
         }),
         ("modelscope", {
             "label": "ModelScope",
diff --git a/common/const.py b/common/const.py
index 0fab180e..abe3c2c1 100644
--- a/common/const.py
+++ b/common/const.py
@@ -87,7 +87,8 @@ DEEPSEEK_V4_FLASH = "deepseek-v4-flash"  # DeepSeek V4 Flash - 默认推荐 (思
 DEEPSEEK_V4_PRO = "deepseek-v4-pro"  # DeepSeek V4 Pro - 复杂任务更强 (思考模式 + 工具调用)
 
 # Baidu Qianfan / ERNIE
-ERNIE_5 = "ernie-5.0"  # ERNIE 5.0 - default recommendation
+ERNIE_5_1 = "ernie-5.1"  # ERNIE 5.1 - default recommendation, latest flagship
+ERNIE_5 = "ernie-5.0"  # ERNIE 5.0
 ERNIE_X1_1 = "ernie-x1.1"  # ERNIE X1.1 - reasoning-focused, multimodal
 ERNIE_45_TURBO_128K = "ernie-4.5-turbo-128k"
 ERNIE_45_TURBO_32K = "ernie-4.5-turbo-32k"
@@ -170,7 +171,7 @@ MODEL_LIST = [
               DEEPSEEK_V4_FLASH, DEEPSEEK_V4_PRO, DEEPSEEK_CHAT, DEEPSEEK_REASONER,
 
               # Baidu Qianfan / ERNIE
-              QIANFAN, ERNIE_5, ERNIE_X1_1, ERNIE_45_TURBO_128K, ERNIE_45_TURBO_32K, ERNIE_4_TURBO_8K,
+              QIANFAN, ERNIE_5_1, ERNIE_5, ERNIE_X1_1, ERNIE_45_TURBO_128K, ERNIE_45_TURBO_32K, ERNIE_4_TURBO_8K,
               ERNIE_45_TURBO_VL, ERNIE_45_TURBO_VL_32K,
 
               # MiniMax
diff --git a/docs/en/models/index.mdx b/docs/en/models/index.mdx
index ca7cf344..5fae1f7d 100644
--- a/docs/en/models/index.mdx
+++ b/docs/en/models/index.mdx
@@ -6,7 +6,7 @@ description: Supported models and recommended choices for CowAgent
 CowAgent supports mainstream LLMs from domestic and international providers. Model interfaces are implemented in the project's `models/` directory.
 
 <Note>
-  For Agent mode, the following models are recommended based on quality and cost: deepseek-v4-flash, MiniMax-M2.7, claude-sonnet-4-6, gemini-3.1-pro-preview, glm-5.1, qwen3.6-plus, kimi-k2.6, ernie-5.0
+  For Agent mode, the following models are recommended based on quality and cost: deepseek-v4-flash, MiniMax-M2.7, claude-sonnet-4-6, gemini-3.1-pro-preview, glm-5.1, qwen3.6-plus, kimi-k2.6, ernie-5.1
 </Note>
 
 ## Configuration
@@ -22,7 +22,7 @@ You can also use the [LinkAI](https://link-ai.tech) platform interface to flexib
     deepseek-v4-flash, deepseek-v4-pro, and more
   </Card>
   <Card title="Baidu Qianfan / ERNIE" href="/en/models/qianfan">
-    ernie-5.0, ernie-4.5-turbo-128k, and more
+    ernie-5.1, ernie-5.0, ernie-4.5-turbo-128k, and more
   </Card>
   <Card title="MiniMax" href="/en/models/minimax">
     MiniMax-M2.7 and other series models
diff --git a/docs/en/models/qianfan.mdx b/docs/en/models/qianfan.mdx
index 117760f1..aa88d040 100644
--- a/docs/en/models/qianfan.mdx
+++ b/docs/en/models/qianfan.mdx
@@ -7,7 +7,7 @@ Option 1: Native integration (recommended):
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "qianfan_api_key": "",
   "qianfan_api_base": "https://qianfan.baidubce.com/v2"
 }
@@ -15,7 +15,7 @@ Option 1: Native integration (recommended):
 
 | Parameter | Description |
 | --- | --- |
-| `model` | Default recommendation: `ernie-5.0`; also supports `ernie-x1.1`, `ernie-4.5-turbo-128k`, `ernie-4.5-turbo-32k` |
+| `model` | Default recommendation: `ernie-5.1`; also supports `ernie-5.0`, `ernie-x1.1`, `ernie-4.5-turbo-128k`, `ernie-4.5-turbo-32k` |
 | `qianfan_api_key` | Qianfan API key, usually starting with `bce-v3/` |
 | `qianfan_api_base` | Optional, defaults to `https://qianfan.baidubce.com/v2` |
 
@@ -23,7 +23,8 @@ Option 1: Native integration (recommended):
 
 | Model | Use Case |
 | --- | --- |
-| `ernie-5.0` | Default recommendation; latest ERNIE flagship with the strongest overall capability |
+| `ernie-5.1` | Default recommendation; latest ERNIE flagship with the strongest overall capability |
+| `ernie-5.0` | Previous-generation flagship with excellent overall capability |
 | `ernie-x1.1` | Deep-thinking reasoning model with lower hallucination and stronger instruction following / tool calling |
 | `ernie-4.5-turbo-128k` | Long-context and general chat |
 | `ernie-4.5-turbo-32k` | General chat with a balanced context window and cost |
@@ -32,7 +33,7 @@ Option 1: Native integration (recommended):
 
 Once `qianfan_api_key` is configured, Agent mode can auto-discover Qianfan for the Vision tool:
 
-- When the main model itself is multimodal (e.g. `ernie-5.0`, `ernie-x1.1`, `ernie-4.5-turbo-vl`), images are handled directly by the main model with no extra setup.
+- When the main model itself is multimodal (e.g. `ernie-5.1`, `ernie-5.0`, `ernie-x1.1`, `ernie-4.5-turbo-vl`), images are handled directly by the main model with no extra setup.
 - When the main model is text-only (e.g. `ernie-4.5-turbo-128k`), the Vision tool automatically falls back to `ernie-4.5-turbo-vl`.
 
 To force a specific Vision model, set it explicitly in `config.json`:
@@ -51,7 +52,7 @@ Option 2: OpenAI-compatible configuration:
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "bot_type": "openai",
   "open_ai_api_key": "",
   "open_ai_api_base": "https://qianfan.baidubce.com/v2"
diff --git a/docs/en/tools/vision.mdx b/docs/en/tools/vision.mdx
index 2a8545fc..9e9da7f5 100644
--- a/docs/en/tools/vision.mdx
+++ b/docs/en/tools/vision.mdx
@@ -23,7 +23,7 @@ If the current provider fails, the tool automatically tries the next one until i
 | Vendor | Vision Model | Notes |
 | --- | --- | --- |
 | OpenAI / Compatible | Main model | All OpenAI-compatible multimodal models |
-| Baidu Qianfan | Main model | Multimodal main models (e.g. `ernie-5.0`) handle images directly; falls back to `ernie-4.5-turbo-vl` for text-only main models |
+| Baidu Qianfan | Main model | Multimodal main models (e.g. `ernie-5.1`) handle images directly; falls back to `ernie-4.5-turbo-vl` for text-only main models |
 | Qwen (DashScope) | Main model | Via MultiModalConversation API |
 | Claude | Main model | Anthropic native image format |
 | Gemini | Main model | inlineData format |
diff --git a/docs/ja/models/index.mdx b/docs/ja/models/index.mdx
index b1047fb7..d86ada77 100644
--- a/docs/ja/models/index.mdx
+++ b/docs/ja/models/index.mdx
@@ -6,7 +6,7 @@ description: CowAgentがサポートするモデルとおすすめの選択肢
 CowAgentは国内外の主要なLLMをサポートしています。モデルインターフェースはプロジェクトの`models/`ディレクトリに実装されています。
 
 <Note>
-  Agent モードでは、品質とコストのバランスから以下のモデルをおすすめします: deepseek-v4-flash、MiniMax-M2.7、claude-sonnet-4-6、gemini-3.1-pro-preview、glm-5.1、qwen3.6-plus、kimi-k2.6、ernie-5.0
+  Agent モードでは、品質とコストのバランスから以下のモデルをおすすめします: deepseek-v4-flash、MiniMax-M2.7、claude-sonnet-4-6、gemini-3.1-pro-preview、glm-5.1、qwen3.6-plus、kimi-k2.6、ernie-5.1
 </Note>
 
 ## 設定
@@ -22,7 +22,7 @@ CowAgentは国内外の主要なLLMをサポートしています。モデルイ
     deepseek-v4-flash、deepseek-v4-pro など
   </Card>
   <Card title="Baidu Qianfan / ERNIE" href="/ja/models/qianfan">
-    ernie-5.0、ernie-4.5-turbo-128k など
+    ernie-5.1、ernie-5.0、ernie-4.5-turbo-128k など
   </Card>
   <Card title="MiniMax" href="/ja/models/minimax">
     MiniMax-M2.7およびその他のシリーズモデル
diff --git a/docs/ja/models/qianfan.mdx b/docs/ja/models/qianfan.mdx
index 42195812..6e5fde15 100644
--- a/docs/ja/models/qianfan.mdx
+++ b/docs/ja/models/qianfan.mdx
@@ -7,7 +7,7 @@ description: Baidu Qianfan ERNIE モデル設定
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "qianfan_api_key": "",
   "qianfan_api_base": "https://qianfan.baidubce.com/v2"
 }
@@ -15,7 +15,7 @@ description: Baidu Qianfan ERNIE モデル設定
 
 | パラメータ | 説明 |
 | --- | --- |
-| `model` | デフォルトの推奨は `ernie-5.0`。`ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k` も利用できます |
+| `model` | デフォルトの推奨は `ernie-5.1`。`ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k` も利用できます |
 | `qianfan_api_key` | Qianfan API Key。通常は `bce-v3/` で始まります |
 | `qianfan_api_base` | 任意。デフォルトは `https://qianfan.baidubce.com/v2` |
 
@@ -23,7 +23,8 @@ description: Baidu Qianfan ERNIE モデル設定
 
 | モデル | 用途 |
 | --- | --- |
-| `ernie-5.0` | デフォルト推奨。文心の最新フラッグシップモデルで、総合性能が最も強い |
+| `ernie-5.1` | デフォルト推奨。文心の最新フラッグシップモデルで、総合性能が最も強い |
+| `ernie-5.0` | 前世代フラッグシップ。総合性能に優れる |
 | `ernie-x1.1` | 深層推論モデル。ハルシネーションが少なく、指示追従とツール呼び出しが強化 |
 | `ernie-4.5-turbo-128k` | 長いコンテキストと一般的なチャット向け |
 | `ernie-4.5-turbo-32k` | コンテキスト長とコストのバランスが良い一般チャット向け |
@@ -32,7 +33,7 @@ description: Baidu Qianfan ERNIE モデル設定
 
 `qianfan_api_key` を設定すると、Agent モードの Vision ツールは Qianfan を自動検出します：
 
-- 主モデルが多モーダル（`ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-vl` など）の場合は、追加設定なしで主モデルがそのまま画像を処理します。
+- 主モデルが多モーダル（`ernie-5.1`、`ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-vl` など）の場合は、追加設定なしで主モデルがそのまま画像を処理します。
 - 主モデルがテキスト専用（`ernie-4.5-turbo-128k` など）の場合は、Vision ツールが自動的に `ernie-4.5-turbo-vl` にフォールバックします。
 
 特定の Vision モデルを強制したい場合は、`config.json` で明示的に指定できます：
@@ -51,7 +52,7 @@ description: Baidu Qianfan ERNIE モデル設定
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "bot_type": "openai",
   "open_ai_api_key": "",
   "open_ai_api_base": "https://qianfan.baidubce.com/v2"
diff --git a/docs/ja/tools/vision.mdx b/docs/ja/tools/vision.mdx
index 0ddf0444..0c3c9d9a 100644
--- a/docs/ja/tools/vision.mdx
+++ b/docs/ja/tools/vision.mdx
@@ -23,7 +23,7 @@ Vision ツールは多段階の自動選択＋自動フォールバック戦略
 | ベンダー | ビジョンモデル | 説明 |
 | --- | --- | --- |
 | OpenAI / 互換プロトコル | メインモデル | すべての OpenAI 互換マルチモーダルモデルに対応 |
-| Baidu Qianfan | メインモデル | 多モーダルの主モデル（`ernie-5.0` など）は直接画像を処理。テキスト専用主モデルの場合は `ernie-4.5-turbo-vl` に自動フォールバック |
+| Baidu Qianfan | メインモデル | 多モーダルの主モデル（`ernie-5.1` など）は直接画像を処理。テキスト専用主モデルの場合は `ernie-4.5-turbo-vl` に自動フォールバック |
 | 通義千問 (DashScope) | メインモデル | MultiModalConversation API 経由 |
 | Claude | メインモデル | Anthropic ネイティブ画像形式 |
 | Gemini | メインモデル | inlineData 形式 |
diff --git a/docs/models/index.mdx b/docs/models/index.mdx
index e2808b71..afe9798e 100644
--- a/docs/models/index.mdx
+++ b/docs/models/index.mdx
@@ -6,7 +6,7 @@ description: CowAgent 支持的模型及推荐选择
 CowAgent 支持国内外主流厂商的大语言模型，模型接口实现在项目的 `models/` 目录下。
 
 <Note>
-  Agent 模式下推荐使用以下模型，可根据效果及成本综合选择：deepseek-v4-flash、MiniMax-M2.7、claude-sonnet-4-6、gemini-3.1-pro-preview、glm-5.1、qwen3.6-plus、kimi-k2.6、ernie-5.0
+  Agent 模式下推荐使用以下模型，可根据效果及成本综合选择：deepseek-v4-flash、MiniMax-M2.7、claude-sonnet-4-6、gemini-3.1-pro-preview、glm-5.1、qwen3.6-plus、kimi-k2.6、ernie-5.1
 
   同时支持使用 [LinkAI](https://link-ai.tech) 平台接口，可灵活切换多种模型，并支持知识库、工作流、插件等 Agent 能力。
 </Note>
@@ -27,7 +27,7 @@ CowAgent 支持国内外主流厂商的大语言模型，模型接口实现在
     deepseek-v4-flash、deepseek-v4-pro 等
   </Card>
   <Card title="百度千帆 / ERNIE" href="/models/qianfan">
-    ernie-5.0、ernie-4.5-turbo-128k 等
+    ernie-5.1、ernie-5.0、ernie-4.5-turbo-128k 等
   </Card>
   <Card title="MiniMax" href="/models/minimax">
     MiniMax-M2.7 等系列模型
diff --git a/docs/models/qianfan.mdx b/docs/models/qianfan.mdx
index e99550f1..819713e0 100644
--- a/docs/models/qianfan.mdx
+++ b/docs/models/qianfan.mdx
@@ -7,7 +7,7 @@ description: 百度千帆 ERNIE 模型配置
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "qianfan_api_key": "",
   "qianfan_api_base": "https://qianfan.baidubce.com/v2"
 }
@@ -15,7 +15,7 @@ description: 百度千帆 ERNIE 模型配置
 
 | 参数 | 说明 |
 | --- | --- |
-| `model` | 默认推荐使用 `ernie-5.0`；也可使用 `ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k` |
+| `model` | 默认推荐使用 `ernie-5.1`；也可使用 `ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-128k`、`ernie-4.5-turbo-32k` |
 | `qianfan_api_key` | 千帆 API Key，格式通常以 `bce-v3/` 开头 |
 | `qianfan_api_base` | 可选，默认为 `https://qianfan.baidubce.com/v2` |
 
@@ -23,7 +23,8 @@ description: 百度千帆 ERNIE 模型配置
 
 | 模型 | 适用场景 |
 | --- | --- |
-| `ernie-5.0` | 默认推荐，文心新一代旗舰模型，综合能力最强 |
+| `ernie-5.1` | 默认推荐，文心新一代旗舰模型，综合能力最强 |
+| `ernie-5.0` | 上一代旗舰模型，综合能力优异 |
 | `ernie-x1.1` | 深度思考推理模型，幻觉更低、指令遵循与工具调用更强 |
 | `ernie-4.5-turbo-128k` | 长上下文和通用对话 |
 | `ernie-4.5-turbo-32k` | 通用对话，成本和上下文更均衡 |
@@ -32,7 +33,7 @@ description: 百度千帆 ERNIE 模型配置
 
 配置 `qianfan_api_key` 后，Agent 的 Vision 工具可以自动使用千帆视觉模型：
 
-- 当主模型本身是多模态时（如 `ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-vl`），直接由主模型识别图像，无需额外配置
+- 当主模型本身是多模态时（如 `ernie-5.1`、`ernie-5.0`、`ernie-x1.1`、`ernie-4.5-turbo-vl`），直接由主模型识别图像，无需额外配置
 - 当主模型是纯文本时（如 `ernie-4.5-turbo-128k`），Vision 工具会自动 fallback 到 `ernie-4.5-turbo-vl`
 
 如需手动指定 Vision 模型，可在 `config.json` 中显式配置：
@@ -51,7 +52,7 @@ description: 百度千帆 ERNIE 模型配置
 
 ```json
 {
-  "model": "ernie-5.0",
+  "model": "ernie-5.1",
   "bot_type": "openai",
   "open_ai_api_key": "",
   "open_ai_api_base": "https://qianfan.baidubce.com/v2"
diff --git a/docs/tools/vision.mdx b/docs/tools/vision.mdx
index 4fccc800..66cfdebf 100644
--- a/docs/tools/vision.mdx
+++ b/docs/tools/vision.mdx
@@ -24,7 +24,7 @@ Vision 工具采用多级自动选择 + 自动兜底策略，无需手动配置
 | Gemini | 使用主模型 | inlineData 格式 |
 | 豆包 (Doubao) | 使用主模型 | doubao-seed-2-0 系列原生支持 |
 | Kimi (Moonshot) | 使用主模型 | kimi-k2.6、kimi-k2.5 原生支持 |
-| 百度千帆 (Qianfan) | 使用主模型 | 默认使用多模态主模型 (如 ernie-5.0)，主模型不支持时兜底使用 ernie-4.5-turbo-vl |
+| 百度千帆 (Qianfan) | 使用主模型 | 默认使用多模态主模型 (如 ernie-5.1)，主模型不支持时兜底使用 ernie-4.5-turbo-vl |
 | 智谱 AI | glm-5v-turbo | 固定使用视觉专用模型 |
 | MiniMax | MiniMax-Text-01 | 固定使用视觉专用模型 |
 
diff --git a/models/qianfan/qianfan_bot.py b/models/qianfan/qianfan_bot.py
index 5643722b..5bfe6577 100644
--- a/models/qianfan/qianfan_bot.py
+++ b/models/qianfan/qianfan_bot.py
@@ -14,12 +14,13 @@ from models.session_manager import SessionManager
 from .qianfan_session import QianfanSession
 
 DEFAULT_API_BASE = "https://qianfan.baidubce.com/v2"
-DEFAULT_MODEL = const.ERNIE_5
+DEFAULT_MODEL = const.ERNIE_5_1
 DEFAULT_VISION_MODEL = const.ERNIE_45_TURBO_VL
 
 # Qianfan models that natively understand images. Other ERNIE variants
 # are text-only and must not receive image payloads.
 _VISION_CAPABLE_MODELS = {
+    const.ERNIE_5_1,
     const.ERNIE_5,
     const.ERNIE_X1_1,
     const.ERNIE_45_TURBO_VL,
diff --git a/models/qianfan/qianfan_session.py b/models/qianfan/qianfan_session.py
index aebd0594..5bf5d036 100644
--- a/models/qianfan/qianfan_session.py
+++ b/models/qianfan/qianfan_session.py
@@ -3,7 +3,7 @@ from common.log import logger
 
 
 class QianfanSession(Session):
-    def __init__(self, session_id, system_prompt=None, model="ernie-5.0"):
+    def __init__(self, session_id, system_prompt=None, model="ernie-5.1"):
         super().__init__(session_id, system_prompt)
         self.model = model
         self.reset()
diff --git a/tests/test_qianfan_provider.py b/tests/test_qianfan_provider.py
index 053e6a6e..4c7900e5 100644
--- a/tests/test_qianfan_provider.py
+++ b/tests/test_qianfan_provider.py
@@ -16,6 +16,8 @@ class TestQianfanConstantsAndRouting(unittest.TestCase):
     def test_ernie_constants_are_in_model_list(self):
         from common import const
 
+        self.assertEqual(const.ERNIE_5_1, "ernie-5.1")
+        self.assertEqual(const.ERNIE_5, "ernie-5.0")
         self.assertEqual(const.ERNIE_45_TURBO_128K, "ernie-4.5-turbo-128k")
         self.assertEqual(const.ERNIE_45_TURBO_32K, "ernie-4.5-turbo-32k")
         self.assertEqual(const.ERNIE_X1_1, "ernie-x1.1")
@@ -28,11 +30,18 @@ class TestQianfanConstantsAndRouting(unittest.TestCase):
             "ernie-4.5-turbo-vl-32k",
         )
         self.assertIn(const.QIANFAN, const.MODEL_LIST)
+        self.assertIn(const.ERNIE_5_1, const.MODEL_LIST)
+        self.assertIn(const.ERNIE_5, const.MODEL_LIST)
         self.assertIn(const.ERNIE_45_TURBO_128K, const.MODEL_LIST)
         self.assertIn(const.ERNIE_45_TURBO_32K, const.MODEL_LIST)
         self.assertIn(const.ERNIE_X1_1, const.MODEL_LIST)
         self.assertIn(const.ERNIE_45_TURBO_VL, const.MODEL_LIST)
         self.assertIn(const.ERNIE_45_TURBO_VL_32K, const.MODEL_LIST)
+        # ERNIE 5.1 must be ranked before 5.0 so it is presented as the default.
+        self.assertLess(
+            const.MODEL_LIST.index(const.ERNIE_5_1),
+            const.MODEL_LIST.index(const.ERNIE_5),
+        )
 
     def test_qianfan_config_keys_are_available(self):
         import config
@@ -112,7 +121,7 @@ class TestQianfanConstantsAndRouting(unittest.TestCase):
 class TestQianfanBot(unittest.TestCase):
     def _fake_conf(self, values=None):
         data = {
-            "model": "ernie-5.0",
+            "model": "ernie-5.1",
             "qianfan_api_key": "test-qianfan-key",
             "qianfan_api_base": "https://qianfan.baidubce.com/v2",
             "temperature": 0.7,
@@ -150,7 +159,7 @@ class TestQianfanBot(unittest.TestCase):
 
                 bot = QianfanBot()
 
-        self.assertEqual(bot.args["model"], "ernie-5.0")
+        self.assertEqual(bot.args["model"], "ernie-5.1")
 
     def test_reply_text_posts_openai_compatible_payload(self):
         fake_conf = self._fake_conf()
@@ -179,7 +188,7 @@ class TestQianfanBot(unittest.TestCase):
         kwargs = post.call_args.kwargs
         self.assertEqual(url, "https://qianfan.baidubce.com/v2/chat/completions")
         self.assertEqual(kwargs["headers"]["Authorization"], "Bearer test-qianfan-key")
-        self.assertEqual(kwargs["json"]["model"], "ernie-5.0")
+        self.assertEqual(kwargs["json"]["model"], "ernie-5.1")
         self.assertEqual(kwargs["json"]["messages"], [{"role": "user", "content": "你好"}])
 
     def test_reply_text_returns_auth_error_for_401(self):
@@ -224,7 +233,7 @@ class TestQianfanBot(unittest.TestCase):
         post.assert_called_once()
 
     def test_qianfan_bot_supports_vision_for_multimodal_models(self):
-        for model in ("ernie-5.0", "ernie-x1.1", "ernie-4.5-turbo-vl", "ernie-4.5-turbo-vl-32k"):
+        for model in ("ernie-5.1", "ernie-5.0", "ernie-x1.1", "ernie-4.5-turbo-vl", "ernie-4.5-turbo-vl-32k"):
             fake_conf = self._fake_conf({"model": model})
             with patch("models.qianfan.qianfan_bot.conf", return_value=fake_conf):
                 with patch("models.qianfan.qianfan_bot.SessionManager"):
@@ -581,7 +590,7 @@ class TestQianfanDocs(unittest.TestCase):
     def test_readme_documents_native_qianfan_provider(self):
         text = self._read("README.md")
 
-        self.assertIn('"model": "ernie-5.0"', text)
+        self.assertIn('"model": "ernie-5.1"', text)
         self.assertIn('"qianfan_api_key": ""', text)
         self.assertIn('"qianfan_api_base": "https://qianfan.baidubce.com/v2"', text)