diff --git a/backend/internal/service/ratelimit_service.go b/backend/internal/service/ratelimit_service.go
index 4d8009b7..53581574 100644
--- a/backend/internal/service/ratelimit_service.go
+++ b/backend/internal/service/ratelimit_service.go
@@ -152,6 +152,11 @@ func (s *RateLimitService) HandleUpstreamError(ctx context.Context, account *Acc
 			msg := "Credit balance exhausted (400): " + upstreamMsg
 			s.handleAuthError(ctx, account, msg)
 			shouldDisable = true
+		} else if strings.Contains(strings.ToLower(upstreamMsg), "identity verification is required") {
+			// KYC 身份验证要求 → 永久禁用，账号需完成身份验证后才能恢复
+			msg := "Identity verification required (400): " + upstreamMsg
+			s.handleAuthError(ctx, account, msg)
+			shouldDisable = true
 		}
 		// 其他 400 错误（如参数问题）不处理，不禁用账号
 	case 401: