diff --git a/backend/app/service/ApprovalService.php b/backend/app/service/ApprovalService.php
index e43be68..38dff33 100644
--- a/backend/app/service/ApprovalService.php
+++ b/backend/app/service/ApprovalService.php
@@ -233,7 +233,12 @@ class ApprovalService
             $approver = User::find($approverId);
             $approverName = $approver ? $approver->name : '未知';
 
-            if ($this->notificationService && $currentNode) {
+            // 确保 notificationService 已初始化
+            if (!$this->notificationService) {
+                $this->notificationService = new FeishuNotificationService();
+            }
+
+            if ($currentNode) {
                 $this->notificationService->updateMessageCards(
                     $order->id,
                     $currentNode->id,