解决方案

方案一：修改系统 apt-get 更新配置文件
方案二：下载阿里云官方 apt-get 源更新脚本
方案一

cp -a /etc/apt/source.list /etc/apt/source.list.bak //备份/etc/apt/source.list文件
vim /etc/apt/source.list
在最前面添加一下内容

deb http://mirrors.aliyun.com/ubuntu/ precise main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ precise-security main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ precise-proposed main restricted universe multiverse
deb http://mirrors.aliyun.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ precise main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ precise-security main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ precise-proposed main restricted universe multiverse
deb-src http://mirrors.aliyun.com/ubuntu/ precise-backports main restricted universe multiverse

执行 apt-get update 更新一下列表
方案二

1.下载 apt-get 更新源脚本

wget http://oss.aliyuncs.com/aliyunecs/update_source.tgz
2.解压并赋权脚本

tar xvf update_source.tgz
chmod 777 update_source.sh
3.执行该脚本

./update_source.sh