diff --git a/packages/core/src/sheets/__tests__/ranges.spec.ts b/packages/core/src/sheets/__tests__/ranges.spec.ts
new file mode 100644
index 0000000000..071cd60d00
--- /dev/null
+++ b/packages/core/src/sheets/__tests__/ranges.spec.ts
@@ -0,0 +1,48 @@
+/**
+ * Copyright 2023-present DreamNum Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { describe, expect, it } from 'vitest';
+import { isAllFormatInTextRuns } from '../range';
+import type { IDocumentBody } from '../../types/interfaces';
+import { BooleanNumber } from '../../types/enum';
+
+describe('Test isAllFormatInTextRuns', () => {
+    it('should return true when all content is bold', () => {
+        const body: IDocumentBody = {
+            dataStream: 'hello\r\n',
+            textRuns: [{
+                st: 0,
+                ed: 5,
+                ts: { bl: BooleanNumber.TRUE },
+            }],
+        };
+
+        expect(isAllFormatInTextRuns('bl', body)).toBe(BooleanNumber.TRUE);
+    });
+
+    it('should return false when any content is not bold', () => {
+        const body: IDocumentBody = {
+            dataStream: 'hello\r\n',
+            textRuns: [{
+                st: 0,
+                ed: 4,
+                ts: { bl: BooleanNumber.TRUE },
+            }],
+        };
+
+        expect(isAllFormatInTextRuns('bl', body)).toBe(BooleanNumber.FALSE);
+    });
+});
diff --git a/packages/core/src/sheets/range.ts b/packages/core/src/sheets/range.ts
index 67809f83a8..8b4720b12f 100644
--- a/packages/core/src/sheets/range.ts
+++ b/packages/core/src/sheets/range.ts
@@ -47,8 +47,8 @@ export interface IRangeDependencies {
     getStyles(): Readonly<Styles>;
 }
 
-function isAllFormatInTextRuns(key: keyof IStyleBase, body: IDocumentBody): BooleanNumber {
-    const { textRuns = [], paragraphs = [], sectionBreaks = [] } = body;
+export function isAllFormatInTextRuns(key: keyof IStyleBase, body: IDocumentBody): BooleanNumber {
+    const { textRuns = [] } = body;
 
     let len = 0;
 
@@ -84,7 +84,9 @@ function isAllFormatInTextRuns(key: keyof IStyleBase, body: IDocumentBody): Bool
     }
 
     // Ensure textRuns cover all content.
-    return body.dataStream.length - paragraphs.length - sectionBreaks.length === len ? BooleanNumber.TRUE : BooleanNumber.FALSE;
+    const index = body.dataStream.indexOf('\r\n');
+
+    return index === len ? BooleanNumber.TRUE : BooleanNumber.FALSE;
 }
 
 /**
@@ -459,13 +461,13 @@ export class Range {
                 : FontItalic.NORMAL;
         }
 
-        return this.getFontStyles()[0][0];
+        return this._getFontStyles()[0][0];
     }
 
     /**
      * Returns the font styles of the cells in the range.
      */
-    private getFontStyles(): FontItalic[][] {
+    private _getFontStyles(): FontItalic[][] {
         return this._getStyles('it') as FontItalic[][];
     }