diff --git a/gradio_ui.py b/gradio_ui.py
index 86518db..e968c8e 100644
--- a/gradio_ui.py
+++ b/gradio_ui.py
@@ -134,25 +134,35 @@ def toggle_run(
 
 # ---------------- 互斥逻辑 ----------------
 def enforce_input_exclusive_and_toggle_fields(selected):
+    order = ["API Models", "Local Models", "Benchmarks", "Custom Datasets"]
     group1 = {"API Models", "Local Models"}
     group2 = {"Benchmarks", "Custom Datasets"}
 
+    # 在每个互斥组里仅保留最后一次点选的项
     def keep_only_one(group):
         filtered = [item for item in selected if item in group]
-        return filtered[-1:]
+        return filtered[-1:]           # 最后一个（空 list 亦可）
 
-    final_selection = set(selected)
-    final_selection -= group1
-    final_selection |= set(keep_only_one(group1))
+    final_sel = set(selected)
+    final_sel -= group1
+    final_sel |= set(keep_only_one(group1))
+    final_sel -= group2
+    final_sel |= set(keep_only_one(group2))
 
-    final_selection -= group2
-    final_selection |= set(keep_only_one(group2))
+    # ① 保证输出顺序固定
+    final_list = [itm for itm in order if itm in final_sel]
+
+    # ② 只有真正变化时才更新，避免死循环
+    if list(selected) == final_list:
+        input_update = gr.update()     # 不带 value => 不触发二次 change
+    else:
+        input_update = gr.update(value=final_list)
+
+    show_api_fields = "API Models" in final_sel
+    row_update = gr.Row.update(visible=show_api_fields)
+
+    return input_update, row_update
 
-    show_api_fields = "API Models" in final_selection
-    return (
-        gr.update(value=list(final_selection)),
-        gr.Row.update(visible=show_api_fields)
-    )
 
 
 # ---------------- 构建 Gradio UI ----------------