ubuntu默认apt源机器在国外，国内下载速度较慢，所以一般会修改为国内的apt源，本文将介绍如何配置使用阿里apt源加速，步骤如下：

1、备份之前的sources.list文件

cp -ra /etc/apt/sources.list /etc/apt/sources.list.bak

2、修改sources.list文件，执行vi /etc/apt/sources.list，添加如下内容：

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

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

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

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

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

2、更新apt缓存，执行如下命令：

sudo apt update

sudo apt upgrade