diff --git a/nl-plugin/nl-plugin-pmm/src/main/java/org/nl/pmm/modular/stagedetail/service/impl/StageDetailServiceImpl.java b/nl-plugin/nl-plugin-pmm/src/main/java/org/nl/pmm/modular/stagedetail/service/impl/StageDetailServiceImpl.java
index 19a88b5..d025d7b 100644
--- a/nl-plugin/nl-plugin-pmm/src/main/java/org/nl/pmm/modular/stagedetail/service/impl/StageDetailServiceImpl.java
+++ b/nl-plugin/nl-plugin-pmm/src/main/java/org/nl/pmm/modular/stagedetail/service/impl/StageDetailServiceImpl.java
@@ -14,6 +14,7 @@ package org.nl.pmm.modular.stagedetail.service.impl;
 
 import cn.hutool.core.bean.BeanUtil;
 import cn.hutool.core.collection.CollStreamUtil;
+import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.util.ObjectUtil;
 import cn.hutool.core.util.StrUtil;
 import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
@@ -32,6 +33,8 @@ import org.nl.pmm.modular.stagedetail.mapper.StageDetailMapper;
 import org.nl.pmm.modular.stagedetail.service.StageDetailService;
 
 import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 /**
  * 项目阶段明细Service接口实现类
@@ -113,6 +116,78 @@ public class StageDetailServiceImpl extends ServiceImpl<StageDetailMapper, Stage
      */
     @Override
     public List<TreeStageDetailVo> getSuperior(StageDetailTreeParam detailTreeParam) {
-        return List.of();
+        // 查询当前阶段下的所有节点
+        LambdaQueryWrapper<StageDetail> wrapper = new LambdaQueryWrapper<>();
+        wrapper.eq(StageDetail::getStageId, detailTreeParam.getStageId())
+                .orderByAsc(StageDetail::getSeq, StageDetail::getDetailId);
+        List<StageDetail> allDetails = this.list(wrapper);
+        if(CollUtil.isEmpty(allDetails)) {
+            return List.of();
+        }
+
+        // 构建 id -> 节点、 parentId -> children 映射
+        Map<String, TreeStageDetailVo> idNodeMap = allDetails.stream()
+                .map(item -> BeanUtil.copyProperties(item, TreeStageDetailVo.class))
+                .collect(Collectors.toMap(TreeStageDetailVo::getDetailId, item -> item));
+
+        Map<String, List<TreeStageDetailVo>> parentChildrenMap = idNodeMap.values().stream()
+                .collect(Collectors.groupingBy(node -> StrUtil.emptyToNull(node.getParentDetailId())));
+
+        // 组装 children
+        idNodeMap.values().forEach(node -> {
+            List<TreeStageDetailVo> children = parentChildrenMap.getOrDefault(node.getDetailId(), List.of());
+            node.setChildren(children);
+        });
+
+        // 根节点
+        List<TreeStageDetailVo> rootNodes = parentChildrenMap.getOrDefault(null, List.of());
+
+        // 无 parentDetailId 表示取顶层
+        if(StrUtil.isBlank(detailTreeParam.getParentDetailId())) {
+            rootNodes.forEach(node -> node.setIsLeaf(CollUtil.isEmpty(node.getChildren())));
+            return rootNodes;
+        }
+
+        // 计算祖先链（包含目标父节点）
+        String targetParentId = detailTreeParam.getParentDetailId();
+        List<String> ancestorIds = CollUtil.newArrayList();
+        String cursor = targetParentId;
+        while(StrUtil.isNotBlank(cursor)) {
+            ancestorIds.add(cursor);
+            TreeStageDetailVo current = idNodeMap.get(cursor);
+            if(current == null || StrUtil.isBlank(current.getParentDetailId())) {
+                cursor = null;
+            } else {
+                cursor = current.getParentDetailId();
+            }
+        }
+
+        // 构建仅保留祖先链上下级关系的树（顶层节点默认展开一层子节点）
+        return rootNodes.stream()
+                .map(node -> buildPrunedTree(node, ancestorIds, targetParentId, parentChildrenMap))
+                .peek(node -> node.setIsLeaf(CollUtil.isEmpty(node.getChildren())))
+                .collect(Collectors.toList());
+    }
+
+    /**
+     * 仅保留祖先链上节点的子集，顶层节点默认展开一层，其余节点不展开 children。
+     */
+    private TreeStageDetailVo buildPrunedTree(TreeStageDetailVo current,
+                                              List<String> ancestorIds,
+                                              String targetParentId,
+                                              Map<String, List<TreeStageDetailVo>> parentChildrenMap) {
+        TreeStageDetailVo copy = BeanUtil.copyProperties(current, TreeStageDetailVo.class);
+        boolean expandChildren = ancestorIds.contains(current.getDetailId()) || StrUtil.isBlank(current.getParentDetailId());
+        if(expandChildren) {
+            List<TreeStageDetailVo> children = parentChildrenMap.getOrDefault(current.getDetailId(), List.of())
+                    .stream()
+                    .map(child -> buildPrunedTree(child, ancestorIds, targetParentId, parentChildrenMap))
+                    .collect(Collectors.toList());
+            copy.setChildren(children);
+        } else {
+            copy.setChildren(List.of());
+        }
+        copy.setIsLeaf(CollUtil.isEmpty(copy.getChildren()));
+        return copy;
     }
 }
diff --git a/nl-vue/src/api/pmm/stageDetailApi.js b/nl-vue/src/api/pmm/stageDetailApi.js
index 21c83f2..cc3a25a 100644
--- a/nl-vue/src/api/pmm/stageDetailApi.js
+++ b/nl-vue/src/api/pmm/stageDetailApi.js
@@ -24,5 +24,13 @@ export default {
 	// 获取项目阶段明细详情
 	stageDetailDetail(data) {
 		return request('detail', data, 'get')
+	},
+	// 加载当前父节点的所有子节点
+	loadClass(data) {
+		return request('loadClass', data, 'get')
+	},
+	// 加载当前父节点的所有子节点
+	superior(data) {
+		return request('superior', data, 'post')
 	}
 }