sudo vim /etc/apt/sources.list
删掉之前的所有内容，写上如下内容：
deb https://mirrors.aliyun.com/raspbian/raspbian/ buster main non-free contrib
deb-src https://mirrors.aliyun.com/raspbian/raspbian/ buster main non-free contrib
sudo vim /etc/apt/sources.list.d/raspi.list
删掉之前的所有内容，写上如下内容：
deb https://mirrors.aliyun.com/raspbian/raspbian/ buster main
deb-src https://mirrors.aliyun.com/raspbian/raspbian/ buster main
然后执行命令生效：
sudo apt-get update && apt-get upgrade -y
