1.备份/etc/apt/sources.list
#备份
cp /etc/apt/sources.list /etc/apt/sources.list.bak
2.在/etc/apt/sources.list文件前面添加如下条目
#添加阿里源 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
3.最后执行如下命令更新源
##更新 sudo apt-get update sudo apt-get upgrade
4.另外其他几个国内源如下：
中科大源
##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
163源
##163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
##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