diff --git a/src/hooks/useFilterTreeData.ts b/src/hooks/useFilterTreeData.ts
index 9a16b19d..2f764b30 100644
--- a/src/hooks/useFilterTreeData.ts
+++ b/src/hooks/useFilterTreeData.ts
@@ -2,22 +2,18 @@ import * as React from 'react';
 import type { DefaultOptionType, InternalFieldName, TreeSelectProps } from '../TreeSelect';
 import { fillLegacyProps } from '../utils/legacyUtil';
 
-type GetFuncType<T> = T extends boolean ? never : T;
-type FilterFn = GetFuncType<TreeSelectProps['filterTreeNode']>;
+type FilterFn = NonNullable<TreeSelectProps['filterTreeNode']>;
 
-export default (
+const useFilterTreeData = (
   treeData: DefaultOptionType[],
   searchValue: string,
-  {
-    treeNodeFilterProp,
-    filterTreeNode,
-    fieldNames,
-  }: {
+  options: {
     fieldNames: InternalFieldName;
     treeNodeFilterProp: string;
     filterTreeNode: TreeSelectProps['filterTreeNode'];
   },
 ) => {
+  const { fieldNames, treeNodeFilterProp, filterTreeNode } = options;
   const { children: fieldChildren } = fieldNames;
 
   return React.useMemo(() => {
@@ -31,24 +27,24 @@ export default (
         : (_, dataNode) =>
             String(dataNode[treeNodeFilterProp]).toUpperCase().includes(searchValue.toUpperCase());
 
-    function dig(list: DefaultOptionType[], keepAll: boolean = false) {
-      return list.reduce<DefaultOptionType[]>((total, dataNode) => {
-        const children = dataNode[fieldChildren];
+    const filterTreeNodes = (nodes: DefaultOptionType[], keepAll = false): DefaultOptionType[] =>
+      nodes.reduce<DefaultOptionType[]>((filtered, node) => {
+        const children = node[fieldChildren];
+        const isMatch = keepAll || filterOptionFunc(searchValue, fillLegacyProps(node));
+        const filteredChildren = filterTreeNodes(children || [], isMatch);
 
-        const match = keepAll || filterOptionFunc(searchValue, fillLegacyProps(dataNode));
-        const childList = dig(children || [], match);
-
-        if (match || childList.length) {
-          total.push({
-            ...dataNode,
+        if (isMatch || filteredChildren.length) {
+          filtered.push({
+            ...node,
             isLeaf: undefined,
-            [fieldChildren]: childList,
+            [fieldChildren]: filteredChildren,
           });
         }
-        return total;
+        return filtered;
       }, []);
-    }
 
-    return dig(treeData);
+    return filterTreeNodes(treeData);
   }, [treeData, searchValue, fieldChildren, treeNodeFilterProp, filterTreeNode]);
 };
+
+export default useFilterTreeData;
diff --git a/src/hooks/useTreeData.ts b/src/hooks/useTreeData.ts
index 26ffbebd..96ea50ad 100644
--- a/src/hooks/useTreeData.ts
+++ b/src/hooks/useTreeData.ts
@@ -3,45 +3,35 @@ import type { DataNode, SimpleModeConfig } from '../interface';
 import { convertChildrenToData } from '../utils/legacyUtil';
 import type { DefaultOptionType } from '../TreeSelect';
 
-function parseSimpleTreeData(
-  treeData: DataNode[],
-  { id, pId, rootPId }: SimpleModeConfig,
-): DataNode[] {
-  const keyNodes = {};
-  const rootNodeList = [];
-
-  // Fill in the map
-  const nodeList = treeData.map(node => {
-    const clone = { ...node };
-    const key = clone[id];
-    keyNodes[key] = clone;
-    clone.key = clone.key || key;
-    return clone;
+function buildTreeStructure(nodes: DataNode[], config: SimpleModeConfig): DataNode[] {
+  const { id, pId, rootPId } = config;
+  const nodeMap = new Map<string, DataNode>();
+  const rootNodes: DataNode[] = [];
+
+  nodes.forEach(node => {
+    const nodeKey = node[id];
+    const clonedNode = { ...node, key: node.key || nodeKey };
+    nodeMap.set(nodeKey, clonedNode);
   });
 
-  // Connect tree
-  nodeList.forEach(node => {
+  nodeMap.forEach(node => {
     const parentKey = node[pId];
-    const parent = keyNodes[parentKey];
+    const parent = nodeMap.get(parentKey);
 
-    // Fill parent
     if (parent) {
       parent.children = parent.children || [];
       parent.children.push(node);
-    }
-
-    // Fill root tree node
-    if (parentKey === rootPId || (!parent && rootPId === null)) {
-      rootNodeList.push(node);
+    } else if (parentKey === rootPId || rootPId === null) {
+      rootNodes.push(node);
     }
   });
 
-  return rootNodeList;
+  return rootNodes;
 }
 
 /**
- * Convert `treeData` or `children` into formatted `treeData`.
- * Will not re-calculate if `treeData` or `children` not change.
+ * 将 `treeData` 或 `children` 转换为格式化的 `treeData`。
+ * 如果 `treeData` 或 `children` 没有变化，则不会重新计算。
  */
 export default function useTreeData(
   treeData: DataNode[],
@@ -50,14 +40,16 @@ export default function useTreeData(
 ): DefaultOptionType[] {
   return React.useMemo(() => {
     if (treeData) {
-      return simpleMode
-        ? parseSimpleTreeData(treeData, {
-            id: 'id',
-            pId: 'pId',
-            rootPId: null,
-            ...(simpleMode !== true ? simpleMode : {}),
-          })
-        : treeData;
+      if (simpleMode) {
+        const config: SimpleModeConfig = {
+          id: 'id',
+          pId: 'pId',
+          rootPId: null,
+          ...(typeof simpleMode === 'object' ? simpleMode : {}),
+        };
+        return buildTreeStructure(treeData, config);
+      }
+      return treeData;
     }
 
     return convertChildrenToData(children);
diff --git a/src/utils/valueUtil.ts b/src/utils/valueUtil.ts
index 9e940a55..a66ba045 100644
--- a/src/utils/valueUtil.ts
+++ b/src/utils/valueUtil.ts
@@ -10,13 +10,10 @@ export function toArray<T>(value: T | T[]): T[] {
 
 export function fillFieldNames(fieldNames?: FieldNames) {
   const { label, value, children } = fieldNames || {};
-
-  const mergedValue = value || 'value';
-
   return {
     _title: label ? [label] : ['title', 'label'],
-    value: mergedValue,
-    key: mergedValue,
+    value: value || 'value',
+    key: value || 'value',
     children: children || 'children',
   };
 }