diff --git a/hb_server/apps/sam/models.py b/hb_server/apps/sam/models.py
index 1f47f5e..583fe87 100644
--- a/hb_server/apps/sam/models.py
+++ b/hb_server/apps/sam/models.py
@@ -5,6 +5,7 @@ from django.db.models.base import Model
 import django.utils.timezone as timezone
 from django.db.models.query import QuerySet
 
+
 from utils.model import SoftModel, BaseModel
 from apps.mtm.models import Material
 
diff --git a/hb_server/apps/wf/services.py b/hb_server/apps/wf/services.py
index 7fd7026..d78d8f8 100644
--- a/hb_server/apps/wf/services.py
+++ b/hb_server/apps/wf/services.py
@@ -104,7 +104,7 @@ class WfService(object):
                 expression = i['expression'].format(**ticket_all_value)
                 import datetime, time  # 用于支持条件表达式中对时间的操作
                 if eval(expression):
-                    destination_state = State.objects.get(i['expression'].get('target_state'))
+                    destination_state = State.objects.get(pk=i['target_state'])
         return destination_state
     
     @classmethod
diff --git a/hb_server/apps/wf/views.py b/hb_server/apps/wf/views.py
index cd33e99..eb2eaab 100644
--- a/hb_server/apps/wf/views.py
+++ b/hb_server/apps/wf/views.py
@@ -276,6 +276,13 @@ class TicketViewSet(OptimizationMixin, CreateUpdateCustomMixin, CreateModelMixin
             return Response()
         else:
             raise APIException('无需接单')
+    
+    @action(methods=['post'], detail=True, perms_map={'post':'*'})
+    def retreat(self, request, pk=None):
+        """
+        撤回工单，允许创建人在指定状态撤回工单至初始状态，状态设置中开启允许撤回
+        """
+        pass
 
 class TicketFlowViewSet(ListModelMixin, RetrieveModelMixin, GenericViewSet):
     """