cd /etc/apt mv ./source.list ./source.list.bak
vim source.list
deb http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe deb http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe deb-src http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main multiverse restricted universe deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main multiverse restricted universe deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main multiverse restricted universe deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main multiverse restricted universe
:wq 保存退出即可
sudo apt-get update
sudo apt-get upgrade
但这个很耗时，执行上面那一条就可以了
Linux - Ubuntu18.04下更改apt源为阿里云源
原文：https://www.cnblogs.com/poloyy/p/12656883.html