diff --git a/admin/src/views/config/index.vue b/admin/src/views/config/index.vue
index 0af8416..8ae07ac 100644
--- a/admin/src/views/config/index.vue
+++ b/admin/src/views/config/index.vue
@@ -80,6 +80,40 @@
               </div>
             </el-form-item>
 
+            <el-form-item label="用户默认头像" prop="default_avatar">
+              <div class="upload-container">
+                <el-upload
+                  class="avatar-uploader"
+                  :action="uploadUrl"
+                  :headers="uploadHeaders"
+                  :show-file-list="false"
+                  :on-success="handleDefaultAvatarSuccess"
+                  :on-error="handleUploadError"
+                  :before-upload="beforeUpload"
+                  name="file">
+                  <img v-if="appearanceConfig.default_avatar" :src="getImageUrl(appearanceConfig.default_avatar)" class="avatar-preview" />
+                  <div v-else class="upload-placeholder">
+                    <el-icon class="upload-icon"><Plus /></el-icon>
+                    <div class="upload-text">点击上传头像</div>
+                  </div>
+                </el-upload>
+                <div class="upload-info">
+                  <div class="form-tip">建议尺寸: 200x200px</div>
+                  <div class="form-tip">支持格式: PNG, JPG</div>
+                  <div class="form-tip">文件大小: 最大5MB</div>
+                  <div class="form-tip">新用户注册时将使用此头像</div>
+                  <el-button 
+                    v-if="appearanceConfig.default_avatar" 
+                    type="danger" 
+                    size="small" 
+                    text
+                    @click="clearDefaultAvatar">
+                    清除头像
+                  </el-button>
+                </div>
+              </div>
+            </el-form-item>
+
             <el-form-item>
               <el-button type="primary" @click="saveAppearanceConfig" :loading="saving">
                 <el-icon><Check /></el-icon>
@@ -359,7 +393,8 @@ const originalConfigs = reactive({
 
 const appearanceConfig = ref({
   app_logo: '',
-  about_us_image: ''
+  about_us_image: '',
+  default_avatar: ''
 })
 
 const generalConfig = ref({
@@ -553,6 +588,13 @@ const saveAppearanceConfig = async () => {
         description: 'About us section image URL'
       })
       
+      await api.put('/api/v1/admin/config/default_avatar', {
+        value: appearanceConfig.value.default_avatar,
+        type: 'image',
+        category: 'appearance',
+        description: '用户默认头像'
+      })
+      
       // Update original configs
       originalConfigs.appearance = { ...appearanceConfig.value }
       
@@ -803,6 +845,30 @@ const handleAboutSuccess = (response) => {
   }
 }
 
+// Handle default avatar upload success
+const handleDefaultAvatarSuccess = (response) => {
+  if (response.code === 0) {
+    appearanceConfig.value.default_avatar = response.data.url
+    ElMessage.success('默认头像上传成功')
+  } else {
+    ElMessage.error(response.message || '默认头像上传失败')
+  }
+}
+
+// Clear default avatar
+const clearDefaultAvatar = async () => {
+  try {
+    await ElMessageBox.confirm('确定要清除默认头像吗?', '提示', {
+      confirmButtonText: '确定',
+      cancelButtonText: '取消',
+      type: 'warning'
+    })
+    appearanceConfig.value.default_avatar = ''
+  } catch {
+    // User cancelled
+  }
+}
+
 // Handle QR code upload success
 const handleQrSuccess = (response) => {
   if (response.code === 0) {
@@ -996,6 +1062,42 @@ onMounted(() => {
   display: block;
 }
 
+.avatar-uploader {
+  border: 2px dashed #d9d9d9;
+  border-radius: 8px;
+  cursor: pointer;
+  position: relative;
+  overflow: hidden;
+  transition: all 0.3s;
+  background-color: #fafafa;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 200px;
+  height: 200px;
+}
+
+.avatar-uploader:hover {
+  border-color: #409eff;
+  background-color: #f0f7ff;
+}
+
+.avatar-uploader :deep(.el-upload) {
+  width: 100%;
+  height: 100%;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.avatar-preview {
+  width: 200px;
+  height: 200px;
+  object-fit: cover;
+  display: block;
+  border-radius: 50%;
+}
+
 .upload-info {
   display: flex;
   flex-direction: column;
diff --git a/backend/run-migration.js b/backend/run-migration.js
new file mode 100644
index 0000000..2a83b39
--- /dev/null
+++ b/backend/run-migration.js
@@ -0,0 +1,122 @@
+/**
+ * Safe migration script - checks if columns exist before renaming
+ */
+const { sequelize } = require('./src/config/database');
+
+async function runMigration() {
+  try {
+    console.log('Connecting to database...');
+    await sequelize.authenticate();
+    console.log('Connected successfully!\n');
+
+    // Check and rename hot_services.name_pt to name_es
+    console.log('Checking hot_services table...');
+    const [hotServiceCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `hot_services` LIKE 'name_pt'"
+    );
+    
+    if (hotServiceCols.length > 0) {
+      console.log('Renaming hot_services.name_pt to name_es...');
+      await sequelize.query(
+        "ALTER TABLE `hot_services` CHANGE COLUMN `name_pt` `name_es` VARCHAR(100) NOT NULL"
+      );
+      console.log('✓ hot_services.name_pt renamed to name_es');
+    } else {
+      console.log('✓ hot_services.name_es already exists, skipping...');
+    }
+
+    // Check and rename category.name_pt to name_es
+    console.log('\nChecking category table...');
+    const [categoryCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `category` LIKE 'name_pt'"
+    );
+    
+    if (categoryCols.length > 0) {
+      console.log('Renaming category.name_pt to name_es...');
+      await sequelize.query(
+        "ALTER TABLE `category` CHANGE COLUMN `name_pt` `name_es` VARCHAR(100) NOT NULL"
+      );
+      console.log('✓ category.name_pt renamed to name_es');
+    } else {
+      console.log('✓ category.name_es already exists, skipping...');
+    }
+
+    // Check and rename service.title_pt and description_pt
+    console.log('\nChecking service table...');
+    const [serviceTitleCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `service` LIKE 'title_pt'"
+    );
+    
+    if (serviceTitleCols.length > 0) {
+      console.log('Renaming service.title_pt to title_es...');
+      await sequelize.query(
+        "ALTER TABLE `service` CHANGE COLUMN `title_pt` `title_es` VARCHAR(200) NOT NULL"
+      );
+      console.log('✓ service.title_pt renamed to title_es');
+    } else {
+      console.log('✓ service.title_es already exists, skipping...');
+    }
+
+    const [serviceDescCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `service` LIKE 'description_pt'"
+    );
+    
+    if (serviceDescCols.length > 0) {
+      console.log('Renaming service.description_pt to description_es...');
+      await sequelize.query(
+        "ALTER TABLE `service` CHANGE COLUMN `description_pt` `description_es` TEXT"
+      );
+      console.log('✓ service.description_pt renamed to description_es');
+    } else {
+      console.log('✓ service.description_es already exists, skipping...');
+    }
+
+    // Check and rename notification fields
+    console.log('\nChecking notification table...');
+    const [notifTitleCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `notification` LIKE 'title_pt'"
+    );
+    
+    if (notifTitleCols.length > 0) {
+      console.log('Renaming notification.title_pt to title_es...');
+      await sequelize.query(
+        "ALTER TABLE `notification` CHANGE COLUMN `title_pt` `title_es` VARCHAR(200) NOT NULL"
+      );
+      console.log('✓ notification.title_pt renamed to title_es');
+    } else {
+      console.log('✓ notification.title_es already exists, skipping...');
+    }
+
+    const [notifContentCols] = await sequelize.query(
+      "SHOW COLUMNS FROM `notification` LIKE 'content_pt'"
+    );
+    
+    if (notifContentCols.length > 0) {
+      console.log('Renaming notification.content_pt to content_es...');
+      await sequelize.query(
+        "ALTER TABLE `notification` CHANGE COLUMN `content_pt` `content_es` TEXT"
+      );
+      console.log('✓ notification.content_pt renamed to content_es');
+    } else {
+      console.log('✓ notification.content_es already exists, skipping...');
+    }
+
+    // Update user language preferences
+    console.log('\nUpdating user language preferences...');
+    const [result] = await sequelize.query(
+      "UPDATE `user` SET language = 'es' WHERE language = 'pt'"
+    );
+    console.log(`✓ Updated ${result.affectedRows || 0} users from 'pt' to 'es'`);
+
+    console.log('\n========================================');
+    console.log('Migration completed successfully!');
+    console.log('========================================');
+    
+    process.exit(0);
+  } catch (error) {
+    console.error('\nMigration failed:', error.message);
+    process.exit(1);
+  }
+}
+
+runMigration();
diff --git a/backend/src/services/authService.js b/backend/src/services/authService.js
index 95f1f72..ea20d39 100644
--- a/backend/src/services/authService.js
+++ b/backend/src/services/authService.js
@@ -4,6 +4,7 @@ const LoginHistory = require('../models/LoginHistory');
 const Invitation = require('../models/Invitation');
 const { generateToken, generateRefreshToken } = require('../utils/jwt');
 const env = require('../config/env');
+const configService = require('./configService');
 
 /**
  * Authentication Service
@@ -64,11 +65,22 @@ const wechatLogin = async (code, userInfo = {}, invitationCode = null, deviceInf
   let user = await User.findOne({ where: { wechatOpenId: openId } });
   
   if (!user) {
+    // Get default avatar from config
+    let defaultAvatar = null;
+    try {
+      const avatarConfig = await configService.getConfig('default_avatar');
+      if (avatarConfig && avatarConfig.value) {
+        defaultAvatar = avatarConfig.value;
+      }
+    } catch (e) {
+      console.error('Failed to get default avatar config:', e);
+    }
+
     // Create new user
     const userData = {
       wechatOpenId: openId,
       nickname: userInfo.nickname || 'User',
-      avatar: userInfo.avatar || null,
+      avatar: userInfo.avatar || defaultAvatar,
       invitationCode: await generateUniqueInvitationCode(),
     };
 
diff --git a/backend/src/services/configService.js b/backend/src/services/configService.js
index adb19b4..7a53f55 100644
--- a/backend/src/services/configService.js
+++ b/backend/src/services/configService.js
@@ -121,7 +121,7 @@ const getPublicConfigs = async () => {
   const configs = await getAllConfigs();
   
   // Filter only public configurations
-  const publicKeys = ['app_logo', 'about_us_image', 'app_name', 'contact_phone', 'contact_email', 'contact_qr_image', 'user_agreement', 'privacy_policy', 'invite_rules'];
+  const publicKeys = ['app_logo', 'about_us_image', 'app_name', 'contact_phone', 'contact_email', 'contact_qr_image', 'user_agreement', 'privacy_policy', 'invite_rules', 'default_avatar'];
   
   const publicConfigs = {};
   configs.forEach(config => {
@@ -140,6 +140,7 @@ const initializeDefaults = async () => {
   const defaults = [
     { key: 'app_logo', value: '', type: 'image', category: 'appearance', description: 'Application logo image URL' },
     { key: 'about_us_image', value: '', type: 'image', category: 'appearance', description: 'About us section image URL' },
+    { key: 'default_avatar', value: '', type: 'image', category: 'appearance', description: '用户默认头像' },
     { key: 'app_name', value: 'Overseas Appointment System', type: 'string', category: 'general', description: 'Application name' },
     { key: 'contact_phone', value: '', type: 'string', category: 'contact', description: 'Contact phone number' },
     { key: 'contact_email', value: '', type: 'string', category: 'contact', description: 'Contact email address' },
diff --git a/miniprogram/src/modules/Config.js b/miniprogram/src/modules/Config.js
index b56df4d..362a3b5 100644
--- a/miniprogram/src/modules/Config.js
+++ b/miniprogram/src/modules/Config.js
@@ -11,8 +11,8 @@ var Config = Config || {}
 
 // API 基础地址
 // 注意:微信小程序开发工具无法访问localhost,需要使用本机IP地址
-// Config.API_BASE_URL = 'https://sub.zpc-xy.com' // 本地开发环境(使用本机IP)
-Config.API_BASE_URL = 'http://localhost:3000' // 本地开发环境(浏览器可用)
+Config.API_BASE_URL = 'https://sub.zpc-xy.com' // 本地开发环境(使用本机IP)
+// Config.API_BASE_URL = 'http://localhost:3000' // 本地开发环境(浏览器可用)
 // Config.API_BASE_URL = 'https://your-production-domain.com' // 生产环境（待配置）
 
 // ============================================