一、前言

Ubuntu默认的软件源在天朝几乎就没用，下载速度有时候以B为单位，想要换的更好的体验就需要试着换成国内源，下面是Ubuntu16 LTS的换源方法：

二、方法

1.备份原始源文件source.list

sudo  cp   /etc/apt/sources.list   /etc/apt/sources.list.bak

2.修改源文件sources.list

2.1更改文件权限使其可编辑

sudo  chmod  777  /etc/apt/sources.list 

2.2打开文件进行编辑

 sudo  vim   /etc/apt/sources.list

2.3删除原来的文件内容，复制下面的任意一个到其中并保存（常用的是阿里源和清华源，推荐阿里源）

阿里源

deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ xenial-proposed main restricted universe multiverse

deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ xenial-proposed main restricted universe multiverse

deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse

清华源：

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse

deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse

deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse

deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse

deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse

deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

3. 更新源

sudo apt update