diff --git a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessServiceImpl.java b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessServiceImpl.java
index 93fc7e2490..7d4fb06ce9 100644
--- a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessServiceImpl.java
+++ b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/process/ProcessServiceImpl.java
@@ -927,6 +927,9 @@ public class ProcessServiceImpl implements ProcessService {
             throw new IllegalArgumentException("Cannot find the process definition for this workflowInstance");
         }
         Map<String, String> cmdParam = JSONUtils.toMap(command.getCommandParam());
+        if(cmdParam == null){
+            cmdParam = new HashMap<>();
+        }
         int processInstanceId = command.getProcessInstanceId();
         if (processInstanceId == 0) {
             processInstance = generateNewProcessInstance(processDefinition, command, cmdParam);