安装nano

yum install nano

使用nano编辑/etc/apt/sources.list

sudo nano /etc/apt/sources.list

将下面的源换掉

#默认源
deb http://mirrordirector.raspbian.org/raspbian/ stretch main contrib non-free rpi
#换成阿里云的
deb http://mirrors.aliyun.com/raspbian/raspbian/ stretch main contrib non-free rpi


#Jessie
#默认源
deb http://mirrordirector.raspbian.org/raspbian/ jessie main contrib non-free rpi
#还是阿里云的
deb http://mirrors.aliyun.com/raspbian/raspbian/ jessie main contrib non-free rpi 

换好Ctrl+X保存退出
然后更新下数据就行了

sudo apt-get update
sudo apt-get upgrade