转载自：https://blog.csdn.net/u011483658/article/details/95012034

打开Ubuntu的终端输入：

    maliao@ubuntu:~$ sudo gedit /etc/apt/sources.list
    [sudo] maliao 的密码： 输入密码回车即可

将镜像地址更改为以下任意一个地址（下面提供了阿里，网易，清华，中科大镜像源地址），保存即可。

主要适用于加速apt-get install xxx命令的速度。

更换好源之后执行下方命令更新：

sudo apt-get update
sudo apt-get upgrade

    #阿里源
    deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
    deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
    deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
    deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
    deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse
    deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse
    deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse
    deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse
    deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse
    deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse

    #网易源
    deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
    deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
    deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
    deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
    deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
    deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
    deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
    deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
    deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
    deb-src http://mirrors.163.com/ubuntu/ bionic-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

    ##中科大源
    deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
    deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
    deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
    deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
    deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
    deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
    deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
    deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
    deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
    deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse