先备份原来的源

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

原来的源文件就存放到sources.list.backup 文件里啦

然后修改源

sudo gedit /etc/apt/sources.list

这样会打开文件，删除里面的所有内容，然后把源复制进去

 
    

 #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

保存文件

更新一下源

sudo apt-get update
sudo apt-get upgrade

然后就可以进行下载啦

sudo apt-get install

再说一下源的选择

如果你是大学学生，那么应该是你自己学校的源最快啦

下面是选择最快的源的方法。找到软件与更新，如果是18.04版本可以在终端输入下面的代码进入

sudo update-manager -c -d

在source code 下选择一个自己合适的。

 

需要等待一会儿，根据自己的网速不同时间而不同。

我的自动选择的结果如下：

点击Choose Server，进入下面的界面：

点击reload将重新更改数据源。

然后再update 和upgrade

下面这些是参考的博文

关于选择镜像源的：

ubuntu18.04下更改软件源方式_zxy131072的博客-CSDN博客_ubuntu18.04设置软件源

Ubuntu 18.04 软件源修改成国内源（文件或界面形式）_晚餐男孩的博客-CSDN博客_ubuntu18.04软件源

镜像源配置的：

Ubuntu--更改国内镜像源（阿里、网易、清华、中科大）_白菜先森的博客-CSDN博客_ubuntu中科大镜像源

ubuntu更改镜像源（软件源）_chonjiang的博客-CSDN博客_ubuntu更改镜像源