Debian 通常会按照一定的规律每隔一段时间发布一个新稳定版。 对每个稳定发行版本，用户可以得到三年的完整支持以及额外两年的长期支持。及时获取更新是对系统安全的尊敬，可以避免一些安全问题。换源或者增加源，还有一个好处就是比如你当前是Debian10（buster），有些软件在Debian 11（bullseye）里才是最新版，那我们追加一个bullseye源可以及时获取最新的软件。
Debian发行版目录
下一代 Debian 正式发行版的代号为 bookworm — 测试（testing）版 — 发布日期尚未确定
Debian 11 (bullseye) — 当前的稳定（stable）版
Debian 10（buster） — 当前的旧的稳定（oldstable）版
Debian 9（stretch） — 更旧的稳定（oldoldstable）版，现有长期支持
Debian 8（jessie） — 已存档版本，现有扩展长期支持
Debian 7（wheezy） — 被淘汰的稳定版
Debian 6.0（squeeze） — 被淘汰的稳定版
Debian GNU/Linux 5.0（lenny） — 被淘汰的稳定版
Debian GNU/Linux 4.0（etch） — 被淘汰的稳定版
Debian GNU/Linux 3.1（sarge） — 被淘汰的稳定版
Debian GNU/Linux 3.0（woody） — 被淘汰的稳定版
Debian GNU/Linux 2.2（potato） — 被淘汰的稳定版
Debian GNU/Linux 2.1（slink） — 被淘汰的稳定版
Debian GNU/Linux 2.0（hamm） — 被淘汰的稳定版
被淘汰的 Debian 正式发行版的网页信息已被原封不动地保留，但是这些发行版本身只能在单独的存档中找到（我觉得也没有人敢用被淘汰的稳定版吧？）。

本文以Debian 10源为例。

一、更新系统安装源

一般我们修改 /etc/apt/sources.list 文件，将 Debian 的默认源地址改成新的地址即可，比如将 http://deb.debian.org 改成中科大的 https://mirrors.ustc.edu.cn，可使用以下这条命令：

sed -i ‘s#https://mirrors.163.com#https://mirrors.ustc.edu.cn#g’ /etc/apt/sources.list

注意，如果安装源是 https 协议的，我们还需要安装软件包 apt-transport-https。执行 apt-get install apt-transport-https，随后再执行 apt-get update 即可。使用https地址，可以避免国内运营商的缓存劫持等，还是有必要使用的，当然你也可以不用。
（此处有个“鸡生蛋蛋生鸡的问题”，apt-transport-https要安装也要源，，，可能还和DNS有关，这个就看各位自行决定怎么操作了）

替换源地址之后请先 apt-get update 更新一下源信息，不然执行一些软件更新是无效的。

二、Debian 10 国内常用镜像源

腾讯云镜像站

deb https://mirrors.cloud.tencent.com/debian/ buster main non-free contrib
deb https://mirrors.cloud.tencent.com/debian/ buster-updates main non-free contrib
deb https://mirrors.cloud.tencent.com/debian/ buster-backports main non-free contrib
deb https://mirrors.cloud.tencent.com/debian-security buster/updates main contrib non-free

deb-src https://mirrors.cloud.tencent.com/debian/ buster main non-free contrib
deb-src https://mirrors.cloud.tencent.com/debian/ buster-updates main non-free contrib
deb-src https://mirrors.cloud.tencent.com/debian/ buster-backports main non-free contrib
deb-src https://mirrors.cloud.tencent.com/debian-security buster/updates main contrib non-free

阿里云镜像站

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

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

华为云镜像站

deb https://mirrors.huaweicloud.com/debian/ buster main contrib non-free
deb https://mirrors.huaweicloud.com/debian/ buster-updates main contrib non-free
deb https://mirrors.huaweicloud.com/debian/ buster-backports main contrib non-free
deb https://mirrors.huaweicloud.com/debian-security/ buster/updates main contrib non-free

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

163镜像站

deb https://mirrors.163.com/debian/ buster main non-free contrib
deb https://mirrors.163.com/debian/ buster-updates main non-free contrib
deb https://mirrors.163.com/debian/ buster-backports main non-free contrib
deb https://mirrors.163.com/debian-security/ buster/updates main non-free contrib

deb-src https://mirrors.163.com/debian/ buster main non-free contrib
deb-src https://mirrors.163.com/debian/ buster-updates main non-free contrib
deb-src https://mirrors.163.com/debian/ buster-backports main non-free contrib
deb-src https://mirrors.163.com/debian-security/ buster/updates main non-free contrib

中科大镜像站（推荐第一）

deb https://mirrors.ustc.edu.cn/debian/ buster main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirrors.ustc.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirrors.ustc.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.ustc.edu.cn/debian/ buster main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirrors.ustc.edu.cn/debian-security/ buster/updates main contrib non-free

上海交大镜像站（推荐第二）

deb https://mirror.sjtu.edu.cn/debian/ buster main contrib non-free
deb https://mirror.sjtu.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirror.sjtu.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirror.sjtu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirror.sjtu.edu.cn/debian/ buster main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirror.sjtu.edu.cn/debian-security/ buster/updates main contrib non-free

清华大学镜像站（推荐第三）

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

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

兰州大学镜像站

deb https://mirror.lzu.edu.cn/debian buster main contrib non-free
deb https://mirror.lzu.edu.cn/debian stable-updates main contrib non-free
deb https://mirror.lzu.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirror.lzu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirror.lzu.edu.cn/debian stable main contrib non-free
deb-src https://mirror.lzu.edu.cn/debian stable-updates main contrib non-free
deb-src https://mirror.lzu.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirror.lzu.edu.cn/debian-security/ buster/updates main contrib non-free

北京外国语大学镜像站

deb https://mirrors.bfsu.edu.cn/debian/ buster main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.bfsu.edu.cn/debian/ buster main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian-security/ buster/updates main contrib non-free

北京交通大学镜像站

deb https://mirror.bjtu.edu.cn/debian/ buster main contrib non-free
deb https://mirror.bjtu.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirror.bjtu.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirror.bjtu.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirror.bjtu.edu.cn/debian/ buster main contrib non-free
deb-src https://mirror.bjtu.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirror.bjtu.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirror.bjtu.edu.cn/debian-security/ buster/updates main contrib non-free

南京大学镜像站

deb https://mirror.nju.edu.cn/debian/ buster main contrib non-free
deb https://mirror.nju.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirror.nju.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirror.nju.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirror.nju.edu.cn/debian/ buster main contrib non-free
deb-src https://mirror.nju.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirror.nju.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirror.nju.edu.cn/debian-security/ buster/updates main contrib non-free

哈尔滨工业大学

deb https://mirrors.hit.edu.cn/debian/ buster main contrib non-free
deb https://mirrors.hit.edu.cn/debian/ buster-updates main contrib non-free
deb https://mirrors.hit.edu.cn/debian/ buster-backports main contrib non-free
deb https://mirrors.hit.edu.cn/debian-security/ buster/updates main contrib non-free

deb-src https://mirrors.hit.edu.cn/debian/ buster main contrib non-free
deb-src https://mirrors.hit.edu.cn/debian/ buster-updates main contrib non-free
deb-src https://mirrors.hit.edu.cn/debian/ buster-backports main contrib non-free
deb-src https://mirrors.hit.edu.cn/debian-security/ buster/updates main contrib non-free

Debian 全球镜像站：https://www.debian.org/mirror/list