换源
先将原始文件做备份：
sudo cp /etc/apt/sources.list /etc/apt/sources_copy.list
打开文件：
sudo vim /etc/apt/sources.list
将源写入文件，这里根据自己的版本去选择对于的源，不知道的话先查询自己的版本
root@Ubuntu:~# cat /etc/os-release
NAME="Ubuntu"
VERSION="20.04.6 LTS (Focal Fossa)"
源
ubuntu 22.04（jammy）
# 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/ubuntu/ jammy main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
# deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
# # deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
# deb-src http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
# 预发布软件源，不建议启用
# deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
# # deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
ubuntu 20.04(focal)版本
deb https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
# deb https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
# deb-src https://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
ubuntu 18.04(bionic)版本
deb https://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
# deb https://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
# deb-src https://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
deb https://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
ubuntu 16.04 版本
deb https://mirrors.aliyun.com/ubuntu/ xenial main
deb-src https://mirrors.aliyun.com/ubuntu/ xenial main
deb https://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb-src https://mirrors.aliyun.com/ubuntu/ xenial-updates main
deb https://mirrors.aliyun.com/ubuntu/ xenial universe
deb-src https://mirrors.aliyun.com/ubuntu/ xenial universe
deb https://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb-src https://mirrors.aliyun.com/ubuntu/ xenial-updates universe
deb https://mirrors.aliyun.com/ubuntu/ xenial-security main
deb-src https://mirrors.aliyun.com/ubuntu/ xenial-security main
deb https://mirrors.aliyun.com/ubuntu/ xenial-security universe
deb-src https://mirrors.aliyun.com/ubuntu/ xenial-security universe