diff --git a/docs/book/4/snippets/c4.md b/docs/book/4/snippets/c4.md
deleted file mode 100644
index 117d6bb..0000000
--- a/docs/book/4/snippets/c4.md
+++ /dev/null
@@ -1,53 +0,0 @@
-# 第 4 章：表单
-
-
-## 使用 Bootstrap-Flask 渲染表单
-
-base.html
-
-```html
-<!DOCTYPE html>
-<html lang="en">
-<head>
-    <meta charset="utf-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
-    <title>HelloFlask</title>
-    {% block styles %}
-    <link rel="stylesheet" href="{{ url_for('static', filename='css/bootstrap.min.css') }}">
-    {% endblock %}
-</head>
-<body>
-    {% block content %}{% endblock %}
-</body>
-</html>
-```
-
-index.html
-
-```html
-{% extends 'base.html' %}
-{% from 'bootstrap5/form.html' import render_field, render_form, render_form_row %}
-
-{% block content %}
-<div class="container">
-    <h1>Render Form with Bootstrap-Flask</h1>
-    <h2>1. render_field</h2>
-    <form method="post">
-        {{ form.csrf_token }}
-        {{ render_field(form.username) }}
-        {{ render_field(form.password) }}
-        {{ render_field(form.remember) }}
-        {{ render_field(form.submit) }}
-    </form>
-    <h2>1. render_form</h2>
-    {{ render_form(form) }}
-    <h2>1. render_form_row</h2>
-    <form method="post">
-        {{ form.csrf_token }}
-        {{ render_form_row([form.username, form.password]) }}
-        {{ render_field(form.remember) }}
-        {{ render_field(form.submit) }}
-    </form>
-</div>
-{% endblock %}
-```
diff --git a/docs/book/4/snippets/index.md b/docs/book/4/snippets/index.md
deleted file mode 100644
index da3b188..0000000
--- a/docs/book/4/snippets/index.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# 代码片段
-
-《Flask Web 开发实战（第 2 版）》第 1~7 章出现的所有代码片段会放到这里，方便读者直接复制到本地运行测试。
-
-点击左侧的章节导航访问对应的代码片段。
-
-为了运行这些示例，建议在本地为每一章创建一个这样的文件目录结构：
-
-```text
-- c1/
-  - templates/
-  - static/
-  - app.py
-  - .flaskenv
-```
diff --git a/mkdocs.yml b/mkdocs.yml
index e23bae3..c3aa2e0 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -59,14 +59,6 @@ nav:
     - 第 2 版（2024）:
       - 主页↗: https://helloflask.com/book/4
       - 示例程序: book/4/example.md
-      - 代码片段:
-        - 主页: book/4/snippets/index.md
-        - 第 1 章：初识 Flask: book/4/snippets/c1.md
-        - 第 2 章：Flask 与 HTTP: book/4/snippets/c2.md
-        - 第 3 章：模板和静态文件: book/4/snippets/c3.md
-        - 第 4 章：表单: book/4/snippets/c4.md
-        - 第 5 章：数据库: book/4/snippets/c5.md
-        - 第 6 章：电子邮件: book/4/snippets/c6.md
   - Flask 入门教程:
     - 主页↗: https://helloflask.com/book/3
     - GitHub↗: https://github.com/helloflask/flask-tutorial
