一、执行如下命令打开apt配置文件：
vim /etc/apt/sources.list
二、分别添加官方、中科大、华为云镜像源：
deb http://ports.ubuntu.com/ bionic main restricted universe multiverse
deb-src http://ports.ubuntu.com/ bionic main restricted universe multiverse
deb http://ports.ubuntu.com/ bionic-updates main restricted universe multiverse
deb-src http://ports.ubuntu.com/ bionic-updates main restricted universe multiverse
deb http://ports.ubuntu.com/ bionic-security main restricted universe multiverse
deb-src http://ports.ubuntu.com/ bionic-security main restricted universe multiverse
deb http://ports.ubuntu.com/ bionic-backports main restricted universe multiverse
deb-src http://ports.ubuntu.com/ bionic-backports main restricted universe multiverse
deb http://ports.ubuntu.com/ubuntu-ports/ bionic main universe restricted
deb-src http://ports.ubuntu.com/ubuntu-ports/ bionic main universe restricted
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-updates multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-backports main restricted universe multiverse
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security main restricted
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security universe
deb http://mirrors.ustc.edu.cn/ubuntu-ports/ bionic-security multiverse
deb https://repo.huaweicloud.com/ubuntu-ports/ bionic main restricted universe multiverse
deb-src https://repo.huaweicloud.com/ubuntu-ports/ bionic main restricted universe multiverse
deb https://repo.huaweicloud.com/ubuntu-ports/ bionic-security main restricted universe multiverse
deb-src https://repo.huaweicloud.com/ubuntu-ports/ bionic-security main restricted universe multiverse
deb https://repo.huaweicloud.com/ubuntu-ports/ bionic-updates main restricted universe multiverse
deb-src https://repo.huaweicloud.com/ubuntu-ports/ bionic-updates main restricted universe multiverse
deb https://repo.huaweicloud.com/ubuntu-ports/ bionic-backports main restricted universe multiverse
deb-src https://repo.huaweicloud.com/ubuntu-ports/ bionic-backports main restricted universe multiverse
## Not recommended
# deb https://repo.huaweicloud.com/ubuntu-ports/ bionic-proposed main restricted universe multiverse
三、更新软件列表：
$ sudo apt-get update
四、更新软件包：
$ sudo apt-get upgrade
注意：使用以下命令可自动替换为华为云镜像源：
$ wget -O /etc/apt/sources.list https://repo.huaweicloud.com/repository/conf/Ubuntu-Ports-bionic.list