diff --git a/workflow-engine-core/src/main/java/cn/axzo/workflow/core/service/impl/BpmnProcessTaskServiceImpl.java b/workflow-engine-core/src/main/java/cn/axzo/workflow/core/service/impl/BpmnProcessTaskServiceImpl.java
index 896bcbc0f..4d8666e0f 100644
--- a/workflow-engine-core/src/main/java/cn/axzo/workflow/core/service/impl/BpmnProcessTaskServiceImpl.java
+++ b/workflow-engine-core/src/main/java/cn/axzo/workflow/core/service/impl/BpmnProcessTaskServiceImpl.java
@@ -132,6 +132,7 @@ import static cn.axzo.workflow.common.enums.BpmnProcessInstanceResultEnum.valueO
 import static cn.axzo.workflow.core.common.code.BpmnInstanceRespCode.PROCESS_INSTANCE_ID_NOT_EXISTS;
 import static cn.axzo.workflow.core.common.code.BpmnInstanceRespCode.PROCESS_INSTANCE_NOT_EXISTS;
 import static cn.axzo.workflow.core.common.code.BpmnInstanceRespCode.PROCESS_TASK_NOT_EXISTS;
+import static cn.axzo.workflow.core.common.code.BpmnTaskRespCode.BACK_NODE_CANNOT_REACHABLE;
 import static cn.axzo.workflow.core.common.code.BpmnTaskRespCode.FIND_TASK_BY_PERSON_ID_ERROR;
 import static cn.axzo.workflow.core.common.code.BpmnTaskRespCode.TASK_REMIND_ERROR_NOT_EXISTS;
 import static cn.axzo.workflow.core.common.utils.BpmnCollectionUtils.convertSet;
@@ -335,6 +336,14 @@ public class BpmnProcessTaskServiceImpl implements BpmnProcessTaskService {
     @Override
     @Transactional(rollbackFor = Exception.class)
     public void backTask(BpmnTaskBackAuditDTO dto) {
+        List<BpmnOptionalNodeDTO> backOptionalNodes = getBackOptionalNodes(dto.getTaskId());
+        if (CollectionUtils.isEmpty(backOptionalNodes)) {
+            throw new WorkflowEngineException(BACK_NODE_CANNOT_REACHABLE, dto.getToActivityId());
+        }
+        List<String> activityList = backOptionalNodes.stream().map(BpmnOptionalNodeDTO::getProcessActivityId).collect(Collectors.toList());
+        if (!activityList.contains(dto.getToActivityId())) {
+            throw new WorkflowEngineException(BACK_NODE_CANNOT_REACHABLE, dto.getToActivityId());
+        }
         CommandExecutor commandExecutor = processEngineConfiguration.getCommandExecutor();
         if (Boolean.TRUE.equals(dto.getAsync())) {
             commandExecutor.execute(new CustomBackTaskAsyncCmd(dto));