diff --git a/backend/src/main/java/io/metersphere/track/service/TestCaseService.java b/backend/src/main/java/io/metersphere/track/service/TestCaseService.java
index 481a1e607d..c0767c1f37 100644
--- a/backend/src/main/java/io/metersphere/track/service/TestCaseService.java
+++ b/backend/src/main/java/io/metersphere/track/service/TestCaseService.java
@@ -254,11 +254,16 @@ public class TestCaseService {
     }
 
     private void checkCustomNumExist(TestCaseWithBLOBs testCase) {
+        String id = testCase.getId();
+        TestCaseWithBLOBs testCaseWithBLOBs = testCaseMapper.selectByPrimaryKey(id);
         TestCaseExample example = new TestCaseExample();
-        example.createCriteria()
-                .andCustomNumEqualTo(testCase.getCustomNum())
+        TestCaseExample.Criteria criteria = example.createCriteria();
+        criteria.andCustomNumEqualTo(testCase.getCustomNum())
                 .andProjectIdEqualTo(testCase.getProjectId())
                 .andIdNotEqualTo(testCase.getId());
+        if (testCaseWithBLOBs != null && StringUtils.isNotBlank(testCaseWithBLOBs.getRefId())) {
+            criteria.andRefIdNotEqualTo(testCaseWithBLOBs.getRefId());
+        }
         List<TestCase> list = testCaseMapper.selectByExample(example);
         if (CollectionUtils.isNotEmpty(list)) {
             MSException.throwException(Translator.get("custom_num_is_exist"));