1、先備份好系統自帶的源列表

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

2、修改源列表文件

vi /etc/apt/sources.list

刪除系統自帶的源列表【sources.list】里的內容，再將下列源復制粘貼到源列表文件后保存。

注意：要添加一整套源，不要只在源列表中添加1條源

例如：添加阿里源到sources.list中

163源：

deb http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse

deb http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ precise main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ precise-security main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ precise-updates main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ precise-proposed main restricted universe multiverse

deb-src http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiverse

阿里源：

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

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

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

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

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

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

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

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

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

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

3、刷新源列表

sudo apt-get update

刷新完成會顯示如下圖所示，由于使用的是阿里源，所以下圖顯示的是阿里源列表信息

使用官方源可能會在更新包時，存在更新緩慢的情況，所以建議使用163或阿里源，國內下載更新首選。