diff --git a/apps/web/src/components/MaterialPickerModal.vue b/apps/web/src/components/MaterialPickerModal.vue
index deabeb0..958bc79 100644
--- a/apps/web/src/components/MaterialPickerModal.vue
+++ b/apps/web/src/components/MaterialPickerModal.vue
@@ -33,28 +33,31 @@
         @click="selectMajor(g.major)"
       >{{ g.major }}</a-tag>
     </div>
-    <!-- 级联：子类 -->
+    <!-- 级联：子类（可多选组合） -->
     <div class="cascade-row" v-if="currentSubs.length">
       <span class="cascade-lbl">子类</span>
       <a-tag
-        :color="sub === null ? '#b4232a' : 'default'"
+        :color="!subs.length ? '#b4232a' : 'default'"
         class="cas-tag"
-        @click="selectSub(null)"
+        @click="clearSubs"
       >全部</a-tag>
       <a-tag
         v-for="s in currentSubs"
         :key="s"
-        :color="sub === s ? '#b4232a' : 'default'"
+        :color="subs.includes(s) ? '#b4232a' : 'default'"
         class="cas-tag"
-        @click="selectSub(s)"
-      >{{ s }}</a-tag>
+        @click="toggleSub(s)"
+      >
+        <CheckOutlined v-if="subs.includes(s)" /> {{ s }}
+      </a-tag>
+      <span v-if="subs.length" class="multi-tip">已选 {{ subs.length }} 个子类（组合）</span>
     </div>
 
     <a-divider style="margin: 10px 0" />
 
     <!-- 当前类别材料 -->
     <div class="list-head">
-      <span>{{ major }}<template v-if="sub"> / {{ sub }}</template> · 共 {{ list.length }} 种</span>
+      <span>{{ major }}<template v-if="subs.length"> / {{ subs.join('、') }}</template> · 共 {{ list.length }} 种</span>
       <a-button type="primary" size="small" :disabled="checkedCount === 0" @click="addSelected">
         批量添加所选（{{ checkedCount }}）
       </a-button>
@@ -103,6 +106,7 @@
 <script setup lang="ts">
 import { computed, reactive, ref, watch } from 'vue';
 import { message } from 'ant-design-vue';
+import { CheckOutlined } from '@ant-design/icons-vue';
 import { MATERIAL_CATEGORIES, HEALTH_GRADES, ENV_GRADES } from '@airpredict/shared';
 import { listMaterials, type Material } from '../api/materials';
 
@@ -119,9 +123,16 @@ const scope = ref<'public' | 'self'>('public');
 const healthGrade = ref<string | undefined>(undefined);
 const envGrade = ref<string | undefined>(undefined);
 const major = ref<string>('');
-const sub = ref<string | null>(null);
-const list = ref<Material[]>([]);
+const subs = ref<string[]>([]); // 多选子类（组合筛选）
+const fullList = ref<Material[]>([]); // 当前大类全部材料（服务端按健康/环保筛过）
 const loading = ref(false);
+
+// 按已选子类做客户端组合过滤；未选=显示整个大类
+const list = computed(() => {
+  if (!subs.value.length) return fullList.value;
+  const set = new Set(subs.value.map((s) => `${major.value}/${s}`));
+  return fullList.value.filter((m) => set.has(m.category));
+});
 const rowState = reactive<Record<string, { checked: boolean; area: number | null }>>({});
 
 const picked = computed(() => new Set(props.existingIds));
@@ -157,29 +168,33 @@ function healthColor(g: string) {
 
 function selectMajor(m: string) {
   major.value = m;
-  sub.value = null;
+  subs.value = [];
   reload();
 }
-function selectSub(s: string | null) {
-  sub.value = s;
-  reload();
+function toggleSub(s: string) {
+  const i = subs.value.indexOf(s);
+  if (i >= 0) subs.value.splice(i, 1);
+  else subs.value.push(s);
+}
+function clearSubs() {
+  subs.value = [];
 }
 
+// 切大类/健康/环保/库时重新拉整个大类的材料（子类组合在客户端过滤）
 async function reload() {
   if (!major.value) return;
   loading.value = true;
   for (const k of Object.keys(rowState)) delete rowState[k];
   try {
-    const category = sub.value ? `${major.value}/${sub.value}` : major.value;
     const res = await listMaterials({
-      category,
+      category: major.value,
       healthGrade: healthGrade.value,
       envGrade: envGrade.value,
       scope: scope.value,
       page: 1,
       pageSize: 300,
     });
-    list.value = res.items;
+    fullList.value = res.items;
   } finally {
     loading.value = false;
   }
@@ -207,7 +222,7 @@ watch(
   (o) => {
     if (o) {
       if (!major.value) major.value = tree.value[0]?.major || '';
-      sub.value = null;
+      subs.value = [];
       reload();
     }
   },
@@ -220,6 +235,7 @@ watch(
 .cascade-row { display: flex; align-items: center; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
 .cascade-lbl { color: #999; font-size: 12px; width: 32px; flex-shrink: 0; }
 .cas-tag { cursor: pointer; user-select: none; margin: 0; }
+.multi-tip { color: #b4232a; font-size: 12px; margin-left: 8px; }
 .list-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 8px; color: #555; }
 .added { color: #999; }
 </style>