来源：https://blog.csdn.net/u0/article/details/

打开Ubuntu的终端输入：

maliao@ubuntu:~$ sudo vim /etc/apt/sources.list

[sudo] maliao 的密码： 输入密码回车即可

将原文件中镜像地址全部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。

更换好源之后执行下方命令更新：

讯享网

sudo apt-get update

    #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

 

如果出现了如下错误：

由于没有公钥，无法验证下列签名： NO_PUBKEY 3B4FE6ACC0B21F32

则解决方法为：

sudo apt-key adv –keyserver hkp://keyserver.ubuntu.com:80 –recv 3B4FE6ACC0B21F32