diff --git a/MDM/Controllers/Process/ProcessOperationController.cs b/MDM/Controllers/Process/ProcessOperationController.cs
index 0c350e2..d9eea5d 100644
--- a/MDM/Controllers/Process/ProcessOperationController.cs
+++ b/MDM/Controllers/Process/ProcessOperationController.cs
@@ -116,9 +116,9 @@ namespace MDM.Controllers.Process
 
         //TODO 下拉工艺路线
         [HttpGet("SelectRouting")]
-        public IActionResult SelectRouting(string routingcode)
+        public IActionResult SelectRouting(string? routingcode)
         {
-            var response = _ProcessOperationService.SelectRouting(routingcode);
+            var response = _ProcessOperationService.SelectRouting(routingcode??"");
 
             return SUCCESS(response);
         }
@@ -159,7 +159,7 @@ namespace MDM.Controllers.Process
         [HttpGet("get_flow")]
         public IActionResult GetFlow(string? flow_type_code)
         {
-            var response = _ProcessOperationService.GetFlow(flow_type_code);
+            var response = _ProcessOperationService.GetFlow(flow_type_code??"");
             return SUCCESS(response);
         }
 
diff --git a/MDM/Controllers/Process/ProcessOperationWorkstationMappingController.cs b/MDM/Controllers/Process/ProcessOperationWorkstationMappingController.cs
index b0eee0b..b87b815 100644
--- a/MDM/Controllers/Process/ProcessOperationWorkstationMappingController.cs
+++ b/MDM/Controllers/Process/ProcessOperationWorkstationMappingController.cs
@@ -115,9 +115,9 @@ namespace MDM.Controllers.Process
 
         //TODO 下拉工艺路线
         [HttpGet("SelectRouting")]
-        public IActionResult SelectRouting(string routingcode)
+        public IActionResult SelectRouting(string? routingcode)
         {
-            var response = _ProcessOperationWorkstationMappingService.SelectRouting(routingcode);
+            var response = _ProcessOperationWorkstationMappingService.SelectRouting(routingcode??"");
 
             return SUCCESS(response);
         }
diff --git a/MDM/Services/Process/IService/IProcessOperationService.cs b/MDM/Services/Process/IService/IProcessOperationService.cs
index 874b0f4..9ad13f8 100644
--- a/MDM/Services/Process/IService/IProcessOperationService.cs
+++ b/MDM/Services/Process/IService/IProcessOperationService.cs
@@ -32,7 +32,7 @@ namespace MDM.Services.IProcessService
 
         List<ProcessOprerationTransitionDict> QueryProcessOprerationTransitionDict(ProcessOprerationTransitionDictQueryDto parm);
 
-        List<ProcessFlowList>  GetFlow(string? flow_type_code);
+        List<ProcessFlowList>  GetFlow(string flow_type_code);
 
         int BindFlow(ProcessOperationBindFlowDto parm);
 
diff --git a/MDM/Services/Process/ProcessOperationService.cs b/MDM/Services/Process/ProcessOperationService.cs
index 682632c..a2cd7eb 100644
--- a/MDM/Services/Process/ProcessOperationService.cs
+++ b/MDM/Services/Process/ProcessOperationService.cs
@@ -203,7 +203,7 @@ namespace MDM.Services.Process
             return response;
         }
 
-        public List<ProcessFlowList> GetFlow(string? flow_type_code)
+        public List<ProcessFlowList> GetFlow(string flow_type_code)
         {
             var response = Context.Queryable<ProcessFlowList>()
                 .WhereIF(!string.IsNullOrEmpty(flow_type_code), m => m.FlowTypeCode.Contains(flow_type_code))