diff --git a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/application/DatasetApplicationService.java b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/application/DatasetApplicationService.java
index 8f13ac5..7b7c0b4 100644
--- a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/application/DatasetApplicationService.java
+++ b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/application/DatasetApplicationService.java
@@ -113,9 +113,10 @@ public class DatasetApplicationService {
         if (Objects.nonNull(updateDatasetRequest.getStatus())) {
             dataset.setStatus(updateDatasetRequest.getStatus());
         }
-        if (updateDatasetRequest.getParentDatasetId() != null) {
-            handleParentChange(dataset, updateDatasetRequest.getParentDatasetId());
-        }
+        // 处理父数据集变更：始终调用 handleParentChange，以支持设置新的关联或清除关联
+        // handleParentChange 内部通过 normalizeParentId 方法将空字符串和 null 都转换为 null
+        // 这样既支持设置新的父数据集，也支持清除关联
+        handleParentChange(dataset, updateDatasetRequest.getParentDatasetId());
         if (StringUtils.hasText(updateDatasetRequest.getDataSource())) {
             // 数据源id不为空，使用异步线程进行文件扫盘落库
             processDataSourceAsync(dataset.getId(), updateDatasetRequest.getDataSource());