当我们在国内使用Debian 12操作系统的时候，由于网络等多种原因，从Debian 12默认的软件库下载软件包可能会很慢。这就需要我们将默认的软件源更换为国内的镜像源。下面是几个常见的、性能优秀的Debian 12镜像源：
阿里云源
阿里云提供了稳定且实时更新的Debian源，速度有保证。修改/etc/apt/sources.list文件，添加以下内容：
1deb https://mirrors.aliyun.com/debian/ bookworm main non-free non-free-firmware contrib
2deb-src https://mirrors.aliyun.com/debian/ bookworm main non-free non-free-firmware contrib
3deb https://mirrors.aliyun.com/debian-security/ bookworm-security main
4deb-src https://mirrors.aliyun.com/debian-security/ bookworm-security main
5deb https://mirrors.aliyun.com/debian/ bookworm-updates main non-free non-free-firmware contrib
6deb-src https://mirrors.aliyun.com/debian/ bookworm-updates main non-free non-free-firmware contrib
7deb https://mirrors.aliyun.com/debian/ bookworm-backports main non-free non-free-firmware contrib
8deb-src https://mirrors.aliyun.com/debian/ bookworm-backports main non-free non-free-firmware contrib
腾讯云源
腾讯云也提供了Debian镜像源，且更新较快。修改/etc/apt/sources.list文件，添加以下内容：
1deb https://mirrors.cloud.tencent.com/debian/ bookworm main non-free non-free-firmware contrib
2deb-src https://mirrors.cloud.tencent.com/debian/ bookworm main non-free non-free-firmware contrib
3deb https://mirrors.cloud.tencent.com/debian-security/ bookworm-security main
4deb-src https://mirrors.cloud.tencent.com/debian-security/ bookworm-security main
5deb https://mirrors.cloud.tencent.com/debian/ bookworm-updates main non-free non-free-firmware contrib
6deb-src https://mirrors.cloud.tencent.com/debian/ bookworm-updates main non-free non-free-firmware contrib
7deb https://mirrors.cloud.tencent.com/debian/ bookworm-backports main non-free non-free-firmware contrib
8deb-src https://mirrors.cloud.tencent.com/debian/ bookworm-backports main non-free non-free-firmware contrib
清华大学源
清华大学提供了全面而及时的Debian软件包镜像。修改/etc/apt/sources.list文件，添加以下内容：
1deb https://mirrors.tsinghua.edu.cn/debian/ bookworm main non-free non-free-firmware contrib
2deb-src https://mirrors.tsinghua.edu.cn/debian/ bookworm main non-free non-free-firmware contrib
3deb https://mirrors.tsinghua.edu.cn/debian-security/ bookworm-security main
4deb-src https://mirrors.tsinghua.edu.cn/debian-security/ bookworm-security main
5deb https://mirrors.tsinghua.edu.cn/debian/ bookworm-updates main non-free non-free-firmware contrib
6deb-src https://mirrors.tsinghua.edu.cn/debian/ bookworm-updates main non-free non-free-firmware contrib
7deb https://mirrors.tsinghua.edu.cn/debian/ bookworm-backports main non-free non-free-firmware contrib
8deb-src https://mirrors.tsinghua.edu.cn/debian/ bookworm-backports main non-free non-free-firmware contrib
网易源
网易也提供了Debian镜像源，即时性和完整性较好。修改/etc/apt/sources.list文件，添加以下内容：
1deb https://mirrors.163.com/debian/ bookworm main non-free non-free-firmware contrib
2deb-src https://mirrors.163.com/debian/ bookworm main non-free non-free-firmware contrib
3deb https://mirrors.163.com/debian-security/ bookworm-security main
4deb-src https://mirrors.163.com/debian-security/ bookworm-security main
5deb https://mirrors.163.com/debian/ bookworm-updates main non-free non-free-firmware contrib
6deb-src https://mirrors.163.com/debian/ bookworm-updates main non-free non-free-firmware contrib
7deb https://mirrors.163.com/debian/ bookworm-backports main non-free non-free-firmware contrib
8deb-src https://mirrors.163.com/debian/ bookworm-backports main non-free non-free-firmware contrib
中科大源
编辑/etc/apt/sources.list文件，将下面的内容添加进去：
1deb https://mirrors.ustc.edu.cn/debian/ bookworm main non-free non-free-firmware contrib
2deb-src https://mirrors.ustc.edu.cn/debian/ bookworm main non-free non-free-firmware contrib
3deb https://mirrors.ustc.edu.cn/debian-security/ bookworm-security main
4deb-src https://mirrors.ustc.edu.cn/debian-security/ bookworm-security main
5deb https://mirrors.ustc.edu.cn/debian/ bookworm-updates main non-free non-free-firmware contrib
6deb-src https://mirrors.ustc.edu.cn/debian/ bookworm-updates main non-free non-free-firmware contrib
7deb https://mirrors.ustc.edu.cn/debian/ bookworm-backports main non-free non-free-firmware contrib
8deb-src https://mirrors.ustc.edu.cn/debian/ bookworm-backports main non-free non-free-firmware contrib
更新源
编辑完毕后，保存并退出，然后运行以下命令来更新你的软件包列表：
1apt update