diff --git a/src/main/java/cn/palmte/work/service/ActListenerService.java b/src/main/java/cn/palmte/work/service/ActListenerService.java
index 5a9670d..0314b8e 100644
--- a/src/main/java/cn/palmte/work/service/ActListenerService.java
+++ b/src/main/java/cn/palmte/work/service/ActListenerService.java
@@ -71,10 +71,13 @@ public class ActListenerService {
      * @param processInstance
      */
     private void updateProjectApprover(List<String> candidateUsers, ProcessInstance processInstance, String procDefId, String taskDefKey) {
-        String businessKey = processInstance.getBusinessKey();
-        ActTaskDef actTaskDef = actTaskDefService.findFirstByProcDefIdAndTaskKey(procDefId, taskDefKey);
+        if (processInstance == null) {
+            return;
+        }
 
         try {
+            String businessKey = processInstance.getBusinessKey();
+            ActTaskDef actTaskDef = actTaskDefService.findFirstByProcDefIdAndTaskKey(procDefId, taskDefKey);
             int adminId = 0;
             if (!candidateUsers.isEmpty() && actTaskDef!=null && actTaskDef.getTaskIndex() != ActConstant.TASK_INDEX_FIRST_USER_TASK) {
                 //回退到发起节点 审批人设置为空