diff --git a/README.md b/README.md
index d6b9b30..f576c0b 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ A text-to-speech web application based on Qwen3-TTS, supporting custom voice, vo
 - Custom Voice: Predefined speaker voices
 - Voice Design: Create voices from natural language descriptions
 - Voice Cloning: Clone voices from uploaded audio
+- Dual Backend Support: Switch between local model and Aliyun TTS API
 - JWT auth, async tasks, voice cache, dark mode
 
 ## Tech Stack
@@ -26,7 +27,9 @@ python -m venv venv
 source venv/bin/activate
 pip install -r requirements.txt
 cp .env.example .env
-# Edit .env to configure MODEL_BASE_PATH etc.
+# Edit .env to configure MODEL_BASE_PATH and DEFAULT_BACKEND
+# For local model: Ensure MODEL_BASE_PATH points to Qwen model directory
+# For Aliyun: Set DEFAULT_BACKEND=aliyun and configure API key in web settings
 uvicorn main:app --host 0.0.0.0 --port 8000 --reload
 ```
 
@@ -49,6 +52,8 @@ Visit `http://localhost:5173`
 
 ## Configuration
 
+### Backend Configuration
+
 Backend `.env` key settings:
 
 ```env
@@ -56,26 +61,75 @@ SECRET_KEY=your-secret-key
 MODEL_DEVICE=cuda:0
 MODEL_BASE_PATH=../Qwen
 DATABASE_URL=sqlite:///./qwen_tts.db
+
+DEFAULT_BACKEND=local
+
+ALIYUN_REGION=beijing
+ALIYUN_MODEL_FLASH=qwen3-tts-flash-realtime
+ALIYUN_MODEL_VC=qwen3-tts-vc-realtime-2026-01-15
+ALIYUN_MODEL_VD=qwen3-tts-vd-realtime-2026-01-15
 ```
 
+**Backend Options:**
+
+- `DEFAULT_BACKEND`: Default TTS backend, options: `local` or `aliyun`
+- **Local Mode**: Uses local Qwen3-TTS model (requires `MODEL_BASE_PATH` configuration)
+- **Aliyun Mode**: Uses Aliyun TTS API (requires users to configure their API keys in settings)
+
+**Aliyun Configuration:**
+
+- Users need to add their Aliyun API keys in the web interface settings page
+- API keys are encrypted and stored securely in the database
+- Superuser can enable/disable local model access for all users
+- To obtain an Aliyun API key, visit the [Aliyun Console](https://dashscope.console.aliyun.com/)
+
+### Frontend Configuration
+
 Frontend `.env`:
 
 ```env
 VITE_API_URL=http://localhost:8000
 ```
 
+## Usage
+
+### Switching Between Backends
+
+1. Log in to the web interface
+2. Navigate to Settings page
+3. Configure your preferred backend:
+   - **Local Model**: Select "本地模型" (requires local model to be enabled by superuser)
+   - **Aliyun API**: Select "阿里云" and add your API key
+4. The selected backend will be used for all TTS operations by default
+5. You can also specify a different backend per request using the `backend` parameter in the API
+
+### Managing Aliyun API Key
+
+1. In Settings page, find the "阿里云 API 密钥" section
+2. Enter your Aliyun API key
+3. Click "更新密钥" to save and validate
+4. The system will verify the key before saving
+5. You can delete the key anytime using the delete button
+
 ## API
 
 ```
 POST /auth/register          - Register
 POST /auth/token             - Login
-POST /tts/custom-voice       - Custom voice
-POST /tts/voice-design       - Voice design
-POST /tts/voice-clone        - Voice cloning
+POST /tts/custom-voice       - Custom voice (supports backend parameter)
+POST /tts/voice-design       - Voice design (supports backend parameter)
+POST /tts/voice-clone        - Voice cloning (supports backend parameter)
 GET  /jobs                   - Job list
 GET  /jobs/{id}/download     - Download result
 ```
 
+**Backend Parameter:**
+
+All TTS endpoints support an optional `backend` parameter to specify the TTS backend:
+- `backend: "local"` - Use local Qwen3-TTS model
+- `backend: "aliyun"` - Use Aliyun TTS API
+- If not specified, uses the user's default backend setting
+
 ## License
 
 Apache-2.0 license 
diff --git a/README.zh.md b/README.zh.md
index 31d6aea..c360ee5 100644
--- a/README.zh.md
+++ b/README.zh.md
@@ -9,6 +9,7 @@
 - 自定义语音：预定义说话人语音
 - 语音设计：自然语言描述创建语音
 - 语音克隆：上传音频克隆语音
+- 双后端支持：支持本地模型和阿里云 TTS API 切换
 - JWT 认证、异步任务、语音缓存、暗黑模式
 
 ## 技术栈
@@ -26,7 +27,9 @@ python -m venv venv
 source venv/bin/activate
 pip install -r requirements.txt
 cp .env.example .env
-# 编辑 .env 配置 MODEL_BASE_PATH 等
+# 编辑 .env 配置 MODEL_BASE_PATH 和 DEFAULT_BACKEND
+# 本地模型：确保 MODEL_BASE_PATH 指向 Qwen 模型目录
+# 阿里云：设置 DEFAULT_BACKEND=aliyun 并在 Web 设置页面配置 API 密钥
 uvicorn main:app --host 0.0.0.0 --port 8000 --reload
 ```
 
@@ -49,6 +52,8 @@ npm run dev
 
 ## 配置
 
+### 后端配置
+
 后端 `.env` 关键配置：
 
 ```env
@@ -56,26 +61,75 @@ SECRET_KEY=your-secret-key
 MODEL_DEVICE=cuda:0
 MODEL_BASE_PATH=../Qwen
 DATABASE_URL=sqlite:///./qwen_tts.db
+
+DEFAULT_BACKEND=local
+
+ALIYUN_REGION=beijing
+ALIYUN_MODEL_FLASH=qwen3-tts-flash-realtime
+ALIYUN_MODEL_VC=qwen3-tts-vc-realtime-2026-01-15
+ALIYUN_MODEL_VD=qwen3-tts-vd-realtime-2026-01-15
 ```
 
+**后端选项：**
+
+- `DEFAULT_BACKEND`: 默认 TTS 后端，可选值：`local` 或 `aliyun`
+- **本地模式**: 使用本地 Qwen3-TTS 模型（需要配置 `MODEL_BASE_PATH`）
+- **阿里云模式**: 使用阿里云 TTS API（需要用户在设置页面配置 API 密钥）
+
+**阿里云配置：**
+
+- 用户需要在 Web 界面的设置页面添加阿里云 API 密钥
+- API 密钥经过加密后安全存储在数据库中
+- 超级管理员可以控制是否为所有用户启用本地模型
+- 获取阿里云 API 密钥，请访问 [阿里云控制台](https://dashscope.console.aliyun.com/)
+
+### 前端配置
+
 前端 `.env`：
 
 ```env
 VITE_API_URL=http://localhost:8000
 ```
 
+## 使用说明
+
+### 切换后端
+
+1. 登录 Web 界面
+2. 进入设置页面
+3. 配置您偏好的后端：
+   - **本地模型**：选择"本地模型"（需要超级管理员启用本地模型）
+   - **阿里云 API**：选择"阿里云"并添加您的 API 密钥
+4. 选择的后端将默认用于所有 TTS 操作
+5. 也可以通过 API 的 `backend` 参数为单次请求指定不同的后端
+
+### 管理阿里云 API 密钥
+
+1. 在设置页面找到"阿里云 API 密钥"部分
+2. 输入您的阿里云 API 密钥
+3. 点击"更新密钥"保存并验证
+4. 系统会在保存前验证密钥的有效性
+5. 可随时使用删除按钮删除密钥
+
 ## API
 
 ```
 POST /auth/register          - 注册
 POST /auth/token             - 登录
-POST /tts/custom-voice       - 自定义语音
-POST /tts/voice-design       - 语音设计
-POST /tts/voice-clone        - 语音克隆
+POST /tts/custom-voice       - 自定义语音（支持 backend 参数）
+POST /tts/voice-design       - 语音设计（支持 backend 参数）
+POST /tts/voice-clone        - 语音克隆（支持 backend 参数）
 GET  /jobs                   - 任务列表
 GET  /jobs/{id}/download     - 下载结果
 ```
 
+**Backend 参数：**
+
+所有 TTS 接口都支持可选的 `backend` 参数来指定使用的 TTS 后端：
+- `backend: "local"` - 使用本地 Qwen3-TTS 模型
+- `backend: "aliyun"` - 使用阿里云 TTS API
+- 如果不指定，则使用用户的默认后端设置
+
 ## 许可证
 
 Apache-2.0 license 
diff --git a/qwen3-tts-frontend/src/pages/Settings.tsx b/qwen3-tts-frontend/src/pages/Settings.tsx
index ccf57e2..5641124 100644
--- a/qwen3-tts-frontend/src/pages/Settings.tsx
+++ b/qwen3-tts-frontend/src/pages/Settings.tsx
@@ -154,24 +154,24 @@ export default function Settings() {
     <div className="h-screen overflow-hidden flex flex-col bg-background">
       <Navbar />
 
-      <main className="flex-1 overflow-y-auto container mx-auto p-6 max-w-[800px]">
-        <div className="space-y-6">
+      <main className="flex-1 overflow-y-auto container mx-auto p-3 sm:p-6 max-w-[800px]">
+        <div className="space-y-3 sm:space-y-6">
           <div>
-            <h1 className="text-3xl font-bold">设置</h1>
-            <p className="text-muted-foreground mt-2">管理您的账户设置和偏好</p>
+            <h1 className="text-2xl sm:text-3xl font-bold">设置</h1>
+            <p className="text-sm sm:text-base text-muted-foreground mt-1 sm:mt-2">管理您的账户设置和偏好</p>
           </div>
 
           <Card>
-            <CardHeader>
-              <CardTitle>后端偏好</CardTitle>
-              <CardDescription>选择默认的 TTS 后端模式</CardDescription>
+            <CardHeader className="p-4 sm:p-6">
+              <CardTitle className="text-lg sm:text-xl">后端偏好</CardTitle>
+              <CardDescription className="text-sm">选择默认的 TTS 后端模式</CardDescription>
             </CardHeader>
-            <CardContent>
+            <CardContent className="p-4 sm:p-6">
               <RadioGroup
                 value={preferences.default_backend}
                 onValueChange={handleBackendChange}
               >
-                <div className={`flex items-center space-x-3 border rounded-lg p-4 ${
+                <div className={`flex items-center space-x-2 sm:space-x-3 border rounded-lg p-3 sm:p-4 ${
                   !isBackendAvailable('local') ? 'opacity-50' : 'hover:bg-accent/50 cursor-pointer'
                 }`}>
                   <RadioGroupItem
@@ -180,18 +180,18 @@ export default function Settings() {
                     disabled={!isBackendAvailable('local')}
                   />
                   <Label htmlFor="backend-local" className="flex-1 cursor-pointer">
-                    <div className="font-medium">本地模型</div>
-                    <div className="text-sm text-muted-foreground">
+                    <div className="font-medium text-sm sm:text-base">本地模型</div>
+                    <div className="text-xs sm:text-sm text-muted-foreground">
                       免费使用本地 Qwen3-TTS 模型
                       {!isBackendAvailable('local') && ' (管理员未启用)'}
                     </div>
                   </Label>
                 </div>
-                <div className="flex items-center space-x-3 border rounded-lg p-4 hover:bg-accent/50 cursor-pointer">
+                <div className="flex items-center space-x-2 sm:space-x-3 border rounded-lg p-3 sm:p-4 hover:bg-accent/50 cursor-pointer">
                   <RadioGroupItem value="aliyun" id="backend-aliyun" />
                   <Label htmlFor="backend-aliyun" className="flex-1 cursor-pointer">
-                    <div className="font-medium">阿里云 API</div>
-                    <div className="text-sm text-muted-foreground">使用阿里云 TTS 服务</div>
+                    <div className="font-medium text-sm sm:text-base">阿里云 API</div>
+                    <div className="text-xs sm:text-sm text-muted-foreground">使用阿里云 TTS 服务</div>
                   </Label>
                 </div>
               </RadioGroup>
@@ -199,21 +199,21 @@ export default function Settings() {
           </Card>
 
           <Card>
-            <CardHeader>
-              <CardTitle>阿里云 API 密钥</CardTitle>
-              <CardDescription>管理您的阿里云 API 密钥配置</CardDescription>
+            <CardHeader className="p-4 sm:p-6">
+              <CardTitle className="text-lg sm:text-xl">阿里云 API 密钥</CardTitle>
+              <CardDescription className="text-sm">管理您的阿里云 API 密钥配置</CardDescription>
             </CardHeader>
-            <CardContent className="space-y-4">
-              <div className="flex items-center gap-2 text-sm">
+            <CardContent className="space-y-3 sm:space-y-4 p-4 sm:p-6">
+              <div className="flex items-center gap-2 text-xs sm:text-sm">
                 <span className="text-muted-foreground">当前状态:</span>
                 {hasAliyunKey ? (
                   <span className="flex items-center gap-1 text-green-600">
-                    <Check className="h-4 w-4" />
+                    <Check className="h-3 w-3 sm:h-4 sm:w-4" />
                     已配置并有效
                   </span>
                 ) : (
                   <span className="flex items-center gap-1 text-muted-foreground">
-                    <X className="h-4 w-4" />
+                    <X className="h-3 w-3 sm:h-4 sm:w-4" />
                     未配置
                   </span>
                 )}
@@ -226,7 +226,7 @@ export default function Settings() {
                     name="api_key"
                     render={({ field }) => (
                       <FormItem>
-                        <FormLabel>API 密钥</FormLabel>
+                        <FormLabel className="text-sm sm:text-base">API 密钥</FormLabel>
                         <FormControl>
                           <div className="flex gap-2">
                             <div className="relative flex-1">
@@ -257,8 +257,8 @@ export default function Settings() {
                     )}
                   />
 
-                  <div className="flex gap-2">
-                    <Button type="submit" disabled={isLoading}>
+                  <div className="flex flex-wrap gap-2">
+                    <Button type="submit" disabled={isLoading} className="flex-1 sm:flex-initial">
                       {isLoading ? '更新中...' : hasAliyunKey ? '更新密钥' : '添加密钥'}
                     </Button>
                     {hasAliyunKey && (
@@ -268,6 +268,7 @@ export default function Settings() {
                           variant="outline"
                           onClick={handleVerifyKey}
                           disabled={isLoading}
+                          className="flex-1 sm:flex-initial"
                         >
                           验证密钥
                         </Button>
@@ -276,9 +277,11 @@ export default function Settings() {
                           variant="destructive"
                           onClick={handleDeleteKey}
                           disabled={isLoading}
+                          size="icon"
+                          className="sm:w-auto sm:px-4"
                         >
-                          <Trash2 className="h-4 w-4 mr-2" />
-                          删除密钥
+                          <Trash2 className="h-4 w-4" />
+                          <span className="hidden sm:inline sm:ml-2">删除密钥</span>
                         </Button>
                       </>
                     )}
@@ -290,16 +293,16 @@ export default function Settings() {
 
           {user.is_superuser && (
             <Card>
-              <CardHeader>
-                <CardTitle>系统设置</CardTitle>
-                <CardDescription>管理全局系统设置（仅管理员可见）</CardDescription>
+              <CardHeader className="p-4 sm:p-6">
+                <CardTitle className="text-lg sm:text-xl">系统设置</CardTitle>
+                <CardDescription className="text-sm">管理全局系统设置（仅管理员可见）</CardDescription>
               </CardHeader>
-              <CardContent>
-                <div className="space-y-4">
-                  <div className="flex items-center justify-between">
-                    <div className="space-y-0.5">
-                      <Label htmlFor="local-model-toggle">启用本地模型</Label>
-                      <p className="text-sm text-muted-foreground">
+              <CardContent className="p-4 sm:p-6">
+                <div className="space-y-3 sm:space-y-4">
+                  <div className="flex items-start sm:items-center justify-between gap-4">
+                    <div className="space-y-0.5 flex-1">
+                      <Label htmlFor="local-model-toggle" className="text-sm sm:text-base">启用本地模型</Label>
+                      <p className="text-xs sm:text-sm text-muted-foreground">
                         允许普通用户在设置中选择并使用本地 Qwen3-TTS 模型
                       </p>
                     </div>
@@ -307,6 +310,7 @@ export default function Settings() {
                       id="local-model-toggle"
                       checked={localModelEnabled}
                       onCheckedChange={handleToggleLocalModel}
+                      className="shrink-0"
                     />
                   </div>
                 </div>
@@ -315,21 +319,21 @@ export default function Settings() {
           )}
 
           <Card>
-            <CardHeader>
-              <CardTitle>账户信息</CardTitle>
-              <CardDescription>您的账户基本信息</CardDescription>
+            <CardHeader className="p-4 sm:p-6">
+              <CardTitle className="text-lg sm:text-xl">账户信息</CardTitle>
+              <CardDescription className="text-sm">您的账户基本信息</CardDescription>
             </CardHeader>
-            <CardContent className="space-y-4">
-              <div className="grid gap-2">
-                <Label>用户名</Label>
+            <CardContent className="space-y-3 sm:space-y-4 p-4 sm:p-6">
+              <div className="grid gap-1.5 sm:gap-2">
+                <Label className="text-sm sm:text-base">用户名</Label>
                 <Input value={user.username} disabled />
               </div>
-              <div className="grid gap-2">
-                <Label>邮箱</Label>
+              <div className="grid gap-1.5 sm:gap-2">
+                <Label className="text-sm sm:text-base">邮箱</Label>
                 <Input value={user.email} disabled />
               </div>
               <div>
-                <Button onClick={() => setShowPasswordDialog(true)}>修改密码</Button>
+                <Button onClick={() => setShowPasswordDialog(true)} className="w-full sm:w-auto">修改密码</Button>
               </div>
             </CardContent>
           </Card>