diff --git a/inventory-backend/app/services/inbound/buy_service.py b/inventory-backend/app/services/inbound/buy_service.py
index 521a2e3..b4b3654 100644
--- a/inventory-backend/app/services/inbound/buy_service.py
+++ b/inventory-backend/app/services/inbound/buy_service.py
@@ -382,7 +382,8 @@ class BuyInboundService:
 
             # 2. 类别独立搜索
             if category and category.strip():
-                query = query.filter(MaterialBase.category == category.strip())
+                # 级联选择器：中间节点用前缀匹配，与 base_service.get_list 行为一致
+                query = query.filter(MaterialBase.category.ilike(f"{category.strip()}%"))
 
             # 3. 类型独立搜索
             if material_type and material_type.strip():
diff --git a/inventory-backend/app/services/inbound/product_service.py b/inventory-backend/app/services/inbound/product_service.py
index b5a7eda..fe5dddf 100644
--- a/inventory-backend/app/services/inbound/product_service.py
+++ b/inventory-backend/app/services/inbound/product_service.py
@@ -349,7 +349,8 @@ class ProductInboundService:
                 sku_str = f'%{sku.strip()}%'
                 query = query.filter(StockProduct.sku.ilike(sku_str))
             if category and category.strip():
-                query = query.filter(MaterialBase.category == category.strip())
+                # 级联选择器：中间节点用前缀匹配，与 base_service.get_list 行为一致
+                query = query.filter(MaterialBase.category.ilike(f"{category.strip()}%"))
             if material_type and material_type.strip():
                 query = query.filter(MaterialBase.material_type == material_type.strip())
 
diff --git a/inventory-backend/app/services/inbound/semi_service.py b/inventory-backend/app/services/inbound/semi_service.py
index beeb0ce..03b6ec5 100644
--- a/inventory-backend/app/services/inbound/semi_service.py
+++ b/inventory-backend/app/services/inbound/semi_service.py
@@ -439,7 +439,8 @@ class SemiInboundService:
                 sku_str = f'%{sku.strip()}%'
                 query = query.filter(StockSemi.sku.ilike(sku_str))
             if category and category.strip():
-                query = query.filter(MaterialBase.category == category.strip())
+                # 级联选择器：中间节点用前缀匹配，与 base_service.get_list 行为一致
+                query = query.filter(MaterialBase.category.ilike(f"{category.strip()}%"))
             if material_type and material_type.strip():
                 query = query.filter(MaterialBase.material_type == material_type.strip())