diff --git a/blocksuite/framework/store/src/reactive/flat-native-y/index.ts b/blocksuite/framework/store/src/reactive/flat-native-y/index.ts
index 8acd33c868..7bee39560c 100644
--- a/blocksuite/framework/store/src/reactive/flat-native-y/index.ts
+++ b/blocksuite/framework/store/src/reactive/flat-native-y/index.ts
@@ -4,19 +4,13 @@ import { Array as YArray, type Map as YMap, type YMapEvent } from 'yjs';
 
 import { BaseReactiveYData } from '../base-reactive-data';
 import { Boxed, type OnBoxedChange } from '../boxed';
-import { y2Native } from '../native-y';
 import { ReactiveYArray } from '../proxy';
 import { type OnTextChange, Text } from '../text';
 import type { ProxyOptions, UnRecord } from '../types';
 import { initializeData } from './initialize';
 import { createProxy } from './proxy';
 import type { OnChange } from './types';
-import {
-  deleteEmptyObject,
-  getFirstKey,
-  isEmptyObject,
-  keyWithoutPrefix,
-} from './utils';
+import { getYEventHandler } from './y-event-handler';
 
 export class ReactiveFlatYMap extends BaseReactiveYData<
   UnRecord,
@@ -32,72 +26,14 @@ export class ReactiveFlatYMap extends BaseReactiveYData<
     const yMap = this._ySource;
     const proxy = this._proxy;
     this._onObserve(event, () => {
-      event.keysChanged.forEach(key => {
-        const type = event.changes.keys.get(key);
-        if (!type) {
-          return;
-        }
-        if (type.action === 'update' || type.action === 'add') {
-          const value = yMap.get(key);
-          const keyName: string = keyWithoutPrefix(key);
-          const firstKey = getFirstKey(keyName);
-          if (this._stashed.has(firstKey)) {
-            return;
-          }
-          this._updateWithYjsSkip(() => {
-            const keys = keyName.split('.');
-            void keys.reduce((acc, key, index, arr) => {
-              if (!acc[key] && index !== arr.length - 1) {
-                acc[key] = {};
-              }
-              if (index === arr.length - 1) {
-                acc[key] = y2Native(value, {
-                  transform: (value, origin) => {
-                    return this._transform(firstKey, value, origin);
-                  },
-                });
-              }
-              return acc[key] as UnRecord;
-            }, proxy as UnRecord);
-          });
-          this._onChange?.(firstKey, false);
-          return;
-        }
-        if (type.action === 'delete') {
-          const keyName: string = keyWithoutPrefix(key);
-          const firstKey = getFirstKey(keyName);
-          if (this._stashed.has(firstKey)) {
-            return;
-          }
-          this._updateWithYjsSkip(() => {
-            const keys = keyName.split('.');
-            void keys.reduce((acc, key, index) => {
-              if (index === keys.length - 1) {
-                delete acc[key];
-                let curr = acc;
-                let parentKey = keys[index - 1];
-                let parent = proxy as UnRecord;
-                let path = keys.slice(0, -2);
-
-                for (let i = keys.length - 2; i > 0; i--) {
-                  for (const pathKey of path) {
-                    parent = parent[pathKey] as UnRecord;
-                  }
-                  if (!isEmptyObject(curr)) {
-                    break;
-                  }
-                  deleteEmptyObject(curr, parentKey, parent);
-                  curr = parent;
-                  parentKey = keys[i - 1];
-                  path = path.slice(0, -1);
-                  parent = proxy as UnRecord;
-                }
-              }
-              return acc[key] as UnRecord;
-            }, proxy as UnRecord);
-          });
-          return;
-        }
+      getYEventHandler({
+        yMap,
+        proxy,
+        stashed: this._stashed,
+        updateWithYjsSkip: this._updateWithYjsSkip,
+        transform: this._transform,
+        onChange: this._onChange,
+        event,
       });
     });
   };
diff --git a/blocksuite/framework/store/src/reactive/flat-native-y/y-event-handler.ts b/blocksuite/framework/store/src/reactive/flat-native-y/y-event-handler.ts
new file mode 100644
index 0000000000..23a01fa8e1
--- /dev/null
+++ b/blocksuite/framework/store/src/reactive/flat-native-y/y-event-handler.ts
@@ -0,0 +1,117 @@
+import type { Map as YMap, YMapEvent } from 'yjs';
+
+import { y2Native } from '../native-y';
+import type { UnRecord } from '../types';
+import {
+  deleteEmptyObject,
+  getFirstKey,
+  isEmptyObject,
+  keyWithoutPrefix,
+} from './utils';
+
+type YEventHandlerOptions = {
+  event: YMapEvent<unknown>;
+  yMap: YMap<unknown>;
+  proxy: UnRecord;
+  stashed: Set<string | number>;
+  updateWithYjsSkip: (fn: () => void) => void;
+  transform: (key: string, value: unknown, origin: unknown) => unknown;
+  onChange?: (key: string, isAdd: boolean) => void;
+};
+
+// update proxy when yjs map changes
+export const getYEventHandler = (options: YEventHandlerOptions) => {
+  const { event } = options;
+  const { keysChanged, changes } = event;
+
+  keysChanged.forEach(key => {
+    const type = changes.keys.get(key);
+    if (!type) return;
+
+    if (type.action === 'update' || type.action === 'add') {
+      return handleUpdateOrAdd(key, options);
+    }
+    if (type.action === 'delete') {
+      return handleDelete(key, options);
+    }
+  });
+};
+
+function isStashed(key: string, stashed: Set<string | number>) {
+  const keyName: string = keyWithoutPrefix(key);
+  const firstKey = getFirstKey(keyName);
+  return stashed.has(firstKey);
+}
+
+function handleUpdateOrAdd(
+  key: string,
+  {
+    yMap,
+    proxy,
+    stashed,
+    updateWithYjsSkip,
+    transform,
+    onChange,
+  }: YEventHandlerOptions
+) {
+  if (isStashed(key, stashed)) {
+    return;
+  }
+  const keyName: string = keyWithoutPrefix(key);
+  const firstKey = getFirstKey(keyName);
+  updateWithYjsSkip(() => {
+    const value = yMap.get(key);
+    const keys = keyName.split('.');
+    void keys.reduce((acc, key, index, arr) => {
+      if (!acc[key] && index !== arr.length - 1) {
+        acc[key] = {};
+      }
+      if (index === arr.length - 1) {
+        acc[key] = y2Native(value, {
+          transform: (value, origin) => transform(firstKey, value, origin),
+        });
+      }
+      return acc[key] as UnRecord;
+    }, proxy as UnRecord);
+  });
+  onChange?.(firstKey, false);
+}
+
+function handleDelete(
+  key: string,
+  { proxy, stashed, updateWithYjsSkip, onChange }: YEventHandlerOptions
+) {
+  if (isStashed(key, stashed)) {
+    return;
+  }
+  const keyName: string = keyWithoutPrefix(key);
+  const firstKey = getFirstKey(keyName);
+  updateWithYjsSkip(() => {
+    const keys = keyName.split('.');
+    void keys.reduce((acc, key, index) => {
+      if (index === keys.length - 1) {
+        delete acc[key];
+        let curr = acc;
+        let parentKey = keys[index - 1];
+        let parent = proxy as UnRecord;
+        let path = keys.slice(0, -2);
+
+        for (let i = keys.length - 2; i > 0; i--) {
+          for (const pathKey of path) {
+            parent = parent[pathKey] as UnRecord;
+          }
+          if (!isEmptyObject(curr)) {
+            break;
+          }
+          deleteEmptyObject(curr, parentKey, parent);
+          curr = parent;
+          parentKey = keys[i - 1];
+          path = path.slice(0, -1);
+          parent = proxy as UnRecord;
+        }
+      }
+      return acc[key] as UnRecord;
+    }, proxy as UnRecord);
+  });
+  onChange?.(firstKey, false);
+}