1、 打开apt源文件，最好用winscp，新手友好
vi /etc/apt/sources.list
2、更改源地址，其他注释了
deb http://security.debian.org/ wheezy/updates main contrib
deb-src http://security.debian.org/ wheezy/updates main contrib
deb http://http.us.debian.org/debian/ stable main
apt-get update