阿里云新安装的Debain系统默认源是官方源，安装软件和更新有点慢，遂更换了国内源
一、备份原版源文件

cp /etc/apt/sources.list /etc/apt/sources.list_bak

二、修改源

:> /etc/apt/sources.list #清空文件
vim /etc/apt/sources.list

ubantu:

#------------------------------------------------------------------------------#
#                            OFFICIAL UBUNTU REPOS                             #
#------------------------------------------------------------------------------#


###### Ubuntu Main Repos
deb mirror://mirrors.ubuntu.com/mirrors.txt bionic main restricted universe multiverse
deb-src mirror://mirrors.ubuntu.com/mirrors.txt bionic main restricted universe multiverse

###### Ubuntu Update Repos
deb mirror://mirrors.ubuntu.com/mirrors.txt bionic-security main restricted universe multiverse
deb mirror://mirrors.ubuntu.com/mirrors.txt bionic-updates main restricted universe multiverse
deb mirror://mirrors.ubuntu.com/mirrors.txt bionic-backports main restricted universe multiverse
deb-src mirror://mirrors.ubuntu.com/mirrors.txt bionic-security main restricted universe multiverse
deb-src mirror://mirrors.ubuntu.com/mirrors.txt bionic-updates main restricted universe multiverse
deb-src mirror://mirrors.ubuntu.com/mirrors.txt bionic-backports main restricted universe multiverse

debian 9：

# aliyun
deb http://mirrors.aliyun.com/debian stretch main contrib non-free
deb-src http://mirrors.aliyun.com/debian stretch main contrib non-free
deb http://mirrors.aliyun.com/debian stretch-updates main contrib non-free
deb-src http://mirrors.aliyun.com/debian stretch-updates main contrib non-free
deb http://mirrors.aliyun.com/debian-security stretch/updates main contrib non-free
deb-src http://mirrors.aliyun.com/debian-security stretch/updates main contrib non-free\

其它版本：https://developer.aliyun.com/mirror/debian

三、应用

apt update

好了，现在已经更换完了，顺便更新下所有应用。

apt -y upgrade

更新和下载速度大大提升！