diff --git a/backend/internal/service/login_sms_service.go b/backend/internal/service/login_sms_service.go
index 298bd31..b0e4d40 100644
--- a/backend/internal/service/login_sms_service.go
+++ b/backend/internal/service/login_sms_service.go
@@ -125,7 +125,7 @@ func (s *LoginSMSService) SendLoginCode(user *model.User, requestIP string) (*Se
 		start, end := chinaDayRange(now)
 		var count int64
 		if err := s.db.Model(&model.LoginSMSCode{}).
-			Where("user_id = ? AND purpose = ? AND created_at >= ? AND created_at < ?", user.ID, smsPurposeLogin, start, end).
+			Where("phone = ? AND purpose = ? AND created_at >= ? AND created_at < ?", phone, smsPurposeLogin, start, end).
 			Count(&count).Error; err != nil {
 			return nil, err
 		}