diff --git a/frontend/mobile-app/lib/core/services/account_service.dart b/frontend/mobile-app/lib/core/services/account_service.dart
index 56ab0cab..1aa382f4 100644
--- a/frontend/mobile-app/lib/core/services/account_service.dart
+++ b/frontend/mobile-app/lib/core/services/account_service.dart
@@ -1411,6 +1411,31 @@ class AccountService {
     }
   }
 
+  /// 验证推荐码是否存在
+  ///
+  /// [referralCode] - 推荐码
+  /// 返回用户信息（如果存在），否则抛出异常
+  Future<Map<String, dynamic>> verifyReferralCode(String referralCode) async {
+    debugPrint('$_tag verifyReferralCode() - 验证推荐码: $referralCode');
+
+    try {
+      final response = await _apiClient.get(
+        '/user/by-referral-code/$referralCode',
+      );
+      debugPrint('$_tag verifyReferralCode() - 推荐码有效');
+
+      final responseData = response.data as Map<String, dynamic>;
+      return responseData['data'] as Map<String, dynamic>? ?? responseData;
+    } on ApiException catch (e) {
+      debugPrint('$_tag verifyReferralCode() - 推荐码无效: $e');
+      throw ApiException('推荐码不存在或无效');
+    } catch (e, stackTrace) {
+      debugPrint('$_tag verifyReferralCode() - 未知异常: $e');
+      debugPrint('$_tag verifyReferralCode() - 堆栈: $stackTrace');
+      throw ApiException('推荐码验证失败: $e');
+    }
+  }
+
   /// 发送短信验证码
   ///
   /// [phoneNumber] - 手机号（中国大陆格式：1开头，11位）
diff --git a/frontend/mobile-app/lib/features/auth/presentation/pages/phone_register_page.dart b/frontend/mobile-app/lib/features/auth/presentation/pages/phone_register_page.dart
index e76c0422..f1d25ec3 100644
--- a/frontend/mobile-app/lib/features/auth/presentation/pages/phone_register_page.dart
+++ b/frontend/mobile-app/lib/features/auth/presentation/pages/phone_register_page.dart
@@ -76,12 +76,12 @@ class _PhoneRegisterPageState extends ConsumerState<PhoneRegisterPage> {
   }
 
   void _onPhoneChanged() {
-    // 清除错误信息
-    if (_errorMessage != null) {
-      setState(() {
+    // 手机号变化时更新按钮状态
+    setState(() {
+      if (_errorMessage != null) {
         _errorMessage = null;
-      });
-    }
+      }
+    });
   }
 
   /// 验证手机号格式
@@ -111,6 +111,14 @@ class _PhoneRegisterPageState extends ConsumerState<PhoneRegisterPage> {
     try {
       final accountService = ref.read(accountServiceProvider);
 
+      // 验证推荐码（如果有）
+      if (widget.inviterReferralCode != null &&
+          widget.inviterReferralCode!.isNotEmpty) {
+        debugPrint('[PhoneRegisterPage] 验证推荐码: ${widget.inviterReferralCode}');
+        await accountService.verifyReferralCode(widget.inviterReferralCode!);
+        debugPrint('[PhoneRegisterPage] 推荐码验证通过');
+      }
+
       // 发送验证码
       debugPrint('[PhoneRegisterPage] 发送验证码...');
       await accountService.sendSmsCode(phone, SmsCodeType.register);