首先备份原设置

cp /etc/apt/sources.list ~/sources.list.bak
cp /etc/apt/sources.list.d/raspi.list ~/raspi.list.bak

修改配置

/etc/apt/sources.list 文件替换内容如下（原内容删除）

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-updates main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bookworm-backports main contrib non-free non-free-firmware
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security bookworm-security main contrib non-free non-free-firmware

/etc/apt/sources.list.d/raspi.list 文件替换内容如下（原内容删除）

deb https://mirrors.tuna.tsinghua.edu.cn/raspberrypi/ bookworm main

这两份文件保存好后，执行：apt-get update -y。换源完成