Debian官方源因为墙的问题导致下载速度很慢，所以需要更换为国内的源。

一般情况下，将 /etc/apt/sources.list 文件中 Debian 默认的源地址 security.debian.org替换为国内的源地址即可，更换完源请执行apt update

# 切换到root权限下

cp /etc/apt/sources.list /etc/apt/sources.list.bak # 备份原有文件

# 打开文件编辑

vi /etc/apt/sources.list

#更换国内源内容

#保存

常见国内源地址

清华大学开源软件镜像站

https://mirrors.tuna.tsinghua.edu.cn/help/debian/

# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free
# deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free
# deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free
# deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free

deb https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free
# deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free

阿里云

https://developer.aliyun.com/mirror/debian?spm=a2c6h.13651102.0.0.6b3e1b114ZUgPn

deb https://mirrors.aliyun.com/debian/ bullseye main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye main non-free contrib
deb https://mirrors.aliyun.com/debian-security/ bullseye-security main
deb-src https://mirrors.aliyun.com/debian-security/ bullseye-security main
deb https://mirrors.aliyun.com/debian/ bullseye-updates main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye-updates main non-free contrib
deb https://mirrors.aliyun.com/debian/ bullseye-backports main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye-backports main non-free contrib

中科大

http://mirrors.ustc.edu.cn/help/debian.html

deb https://mirrors.ustc.edu.cn/debian/ bullseye main
deb-src https://mirrors.ustc.edu.cn/debian/ bullseye main
deb https://mirrors.ustc.edu.cn/debian-security/ bullseye-security main
deb-src https://mirrors.ustc.edu.cn/debian-security/ bullseye-security main
deb https://mirrors.ustc.edu.cn/debian/ bullseye-updates main
deb-src https://mirrors.ustc.edu.cn/debian/ bullseye-updates main

163

http://mirrors.163.com/.help/debian.html

deb http://mirrors.163.com/debian/ bullseye main
deb-src http://mirrors.163.com/debian/ bullseye main
deb http://mirrors.163.com/debian-security/ bullseye-security main
deb-src http://mirrors.163.com/debian-security/ bullseye-security main
deb http://mirrors.163.com/debian/ bullseye-updates main
deb-src http://mirrors.163.com/debian/ bullseye-updates main

注意：使用 HTTPS 可以有效避免国内运营商的缓存劫持，需要安装 apt-transport-https，到但是Debian Buster（Debian 10）及以上版本不需要。

更还源后需要更新

# 删除所有已下载的包文件

apt-get clean

# 更新软件包列表

apt-get update

# 升级系统所有软件

apt-get upgrade