一般情况下，将 /etc/apt/sources.list 文件中 Debian 默认的源地址 http://deb.debian.org/ 替换为镜像地址即可。
Debian Buster 以上版本默认支持 HTTPS 源。如果遇到无法拉取 HTTPS 源的情况，请先使用 HTTP 源并安装：
sudo apt install apt-transport-https ca-certificates先切换至root账户 su root，然后执行命令：
sudo nano /etc/apt/sources.list更换国内软件仓库更新源用户，输入命令进入替换更新源和执行更新：
sudo apt update
sudo apt upgrade# 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.cernet.edu.cn/debian/ bookworm main contrib non-free non-free-firmware
# deb-src https://mirrors.cernet.edu.cn/debian/ bookworm main contrib non-free non-free-firmware
deb https://mirrors.cernet.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
# deb-src https://mirrors.cernet.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
deb https://mirrors.cernet.edu.cn/debian/ bookworm-backports main contrib non-free non-free-firmware
# deb-src https://mirrors.cernet.edu.cn/debian/ bookworm-backports main contrib non-free non-free-firmware
deb https://mirrors.cernet.edu.cn/debian-security bookworm-security main contrib non-free non-free-firmware
# # deb-src https://mirrors.cernet.edu.cn/debian-security bookworm-security main contrib non-free non-free-firmware
deb https://security.debian.org/debian-security bookworm-security main contrib non-free non-free-firmware
# deb-src https://security.debian.org/debian-security bookworm-security main contrib non-free non-free-firmware