diff --git a/frontend/src/views/settings/components/DepartmentManagement.vue b/frontend/src/views/settings/components/DepartmentManagement.vue
index 5f00076..8d14ae5 100644
--- a/frontend/src/views/settings/components/DepartmentManagement.vue
+++ b/frontend/src/views/settings/components/DepartmentManagement.vue
@@ -65,12 +65,20 @@
         <div>
           <h2 class="text-apple-title">使用部门列表</h2>
           <p class="mt-1 text-apple-footnote text-system-label-tertiary">
-            当前共 {{ displayedDepartments.length }} 个部门节点
+            当前共 {{ flatDepartments.length }} 个部门节点，默认折叠显示
           </p>
         </div>
-        <button class="btn-apple-secondary" :disabled="loading" @click="fetchDepartments">
-          刷新
-        </button>
+        <div class="flex items-center gap-2">
+          <button class="btn-apple-secondary" :disabled="loading" @click="expandAll">
+            全部展开
+          </button>
+          <button class="btn-apple-secondary" :disabled="loading" @click="collapseAll">
+            全部收起
+          </button>
+          <button class="btn-apple-secondary" :disabled="loading" @click="fetchDepartments">
+            刷新
+          </button>
+        </div>
       </div>
       <div class="overflow-x-auto">
         <table class="w-full">
@@ -91,7 +99,17 @@
             >
               <td class="py-3 px-4">
                 <div class="flex items-center gap-2" :style="{ paddingLeft: `${department.level * 20}px` }">
-                  <span v-if="department.children_count > 0" class="text-apple-blue">📁</span>
+                  <button
+                    v-if="department.children_count > 0"
+                    class="flex h-5 w-5 items-center justify-center rounded text-system-label-secondary hover:bg-system-gray-6 hover:text-system-label-primary"
+                    @click="toggleExpand(department.id)"
+                  >
+                    {{ expandedIds.has(department.id) ? '▾' : '▸' }}
+                  </button>
+                  <span v-else class="inline-block h-5 w-5"></span>
+                  <span v-if="department.children_count > 0" class="text-apple-blue">
+                    {{ expandedIds.has(department.id) ? '📂' : '📁' }}
+                  </span>
                   <span v-else class="text-system-label-tertiary">📄</span>
                   <div>
                     <div class="font-medium">{{ department.name }}</div>
@@ -219,6 +237,7 @@ type FlatDepartmentNode = DepartmentTreeNode & {
 const loading = ref(false)
 const createLoading = ref(false)
 const updateLoading = ref(false)
+const expandedIds = ref<Set<number>>(new Set())
 
 const filters = reactive({
   keyword: '',
@@ -269,14 +288,58 @@ const parentOptions = computed(() =>
 
 const displayedDepartments = computed(() => {
   const keyword = filters.keyword.trim().toLowerCase()
-  return flatDepartments.value.filter((item) => {
-    const matchKeyword =
-      !keyword ||
-      item.name.toLowerCase().includes(keyword) ||
-      (item.parent_name || '').toLowerCase().includes(keyword)
-    const matchStatus = !filters.status || item.status === filters.status
-    return matchKeyword && matchStatus
-  })
+  const visibleIds = new Set<number>()
+  const matchedIds = new Set<number>()
+  const expanded = expandedIds.value
+
+  const walk = (
+    nodes: DepartmentTreeNode[],
+    level = 0,
+    parentName: string | null = null,
+    parentVisible = true
+  ): FlatDepartmentNode[] => {
+    const list: FlatDepartmentNode[] = []
+
+    for (const node of nodes) {
+      const item: FlatDepartmentNode = {
+        ...node,
+        level,
+        parent_name: parentName,
+        optionLabel: `${level > 0 ? `${'— '.repeat(level)}` : ''}${node.name}`
+      }
+      const matchKeyword =
+        !keyword ||
+        item.name.toLowerCase().includes(keyword) ||
+        (item.parent_name || '').toLowerCase().includes(keyword)
+      const matchStatus = !filters.status || item.status === filters.status
+      const selfMatch = matchKeyword && matchStatus
+      const childList = walk(node.children || [], level + 1, node.name, parentVisible && expanded.has(node.id))
+      const childMatched = childList.some((child) => matchedIds.has(child.id))
+
+      if (selfMatch || childMatched) {
+        matchedIds.add(node.id)
+      }
+
+      const shouldShow = keyword
+        ? selfMatch || childMatched
+        : parentVisible && matchStatus
+
+      if (shouldShow) {
+        visibleIds.add(node.id)
+        list.push(item)
+      }
+
+      if (keyword) {
+        list.push(...childList.filter((child) => matchedIds.has(child.id)))
+      } else if (expanded.has(node.id)) {
+        list.push(...childList.filter((child) => visibleIds.has(child.id)))
+      }
+    }
+
+    return list
+  }
+
+  return walk(treeData.value)
 })
 
 const canCreate = computed(() => createForm.name.trim().length > 0)
@@ -302,6 +365,37 @@ const getTotalEquipmentCount = (dept: FlatDepartmentNode): number => {
 
 const getLevelLabel = (level: number) => `第 ${level + 1} 级`
 
+const collectExpandableIds = (nodes: DepartmentTreeNode[]): number[] => {
+  const ids: number[] = []
+  for (const node of nodes) {
+    if (node.children_count > 0) {
+      ids.push(node.id)
+    }
+    if (node.children?.length) {
+      ids.push(...collectExpandableIds(node.children))
+    }
+  }
+  return ids
+}
+
+const toggleExpand = (id: number) => {
+  const next = new Set(expandedIds.value)
+  if (next.has(id)) {
+    next.delete(id)
+  } else {
+    next.add(id)
+  }
+  expandedIds.value = next
+}
+
+const expandAll = () => {
+  expandedIds.value = new Set(collectExpandableIds(treeData.value))
+}
+
+const collapseAll = () => {
+  expandedIds.value = new Set()
+}
+
 const resetCreateForm = () => {
   createForm.name = ''
   createForm.parent_id = null