diff --git a/frontend/mobile-app/lib/core/services/account_service.dart b/frontend/mobile-app/lib/core/services/account_service.dart
index 9cc09299..8fd2beb7 100644
--- a/frontend/mobile-app/lib/core/services/account_service.dart
+++ b/frontend/mobile-app/lib/core/services/account_service.dart
@@ -883,8 +883,18 @@ class AccountService {
       }
 
       final responseData = response.data as Map<String, dynamic>;
-      final newAvatarUrl = responseData['avatarUrl'] as String;
+      debugPrint('$_tag uploadAvatar() - responseData: $responseData');
+      // API 返回格式: { success: true, data: { message, avatarUrl } }
+      final data = responseData['data'] as Map<String, dynamic>?;
+      debugPrint('$_tag uploadAvatar() - data: $data');
+      if (data == null) {
+        throw const ApiException('上传头像失败: 响应数据格式错误');
+      }
+      final newAvatarUrl = data['avatarUrl'] as String?;
       debugPrint('$_tag uploadAvatar() - 新头像URL: $newAvatarUrl');
+      if (newAvatarUrl == null || newAvatarUrl.isEmpty) {
+        throw const ApiException('上传头像失败: 未返回头像URL');
+      }
 
       // 更新本地存储（使用 avatarUrl 而不是 avatarSvg）
       await _secureStorage.write(key: StorageKeys.avatarUrl, value: newAvatarUrl);