编辑源：
sudo nano /etc/apt/sources.list打开以后，将里面的代码用 # 注释掉，添加如下代码：
deb http://mirrors.aliyun.com/raspbian/raspbian/ wheezy main non-free contrib
deb-src http://mirrors.aliyun.com/raspbian/raspbian/ wheezy main non-free contrib
deb http://mirrors.tuna.tsinghua.edu.cn/raspbian/raspbian/ buster main contrib non-free rpi
deb-src http://mirrors.tuna.tsinghua.edu.cn/raspbian/raspbian/ buster main contrib non-free rpi
sudo nano /etc/apt/sources.list.d/raspi.list打开以后，将里面的代码用 # 注释掉，添加如下代码：
deb http://mirror.tuna.tsinghua.edu.cn/raspberrypi/ buster main ui
deb-src http://mirror.tuna.tsinghua.edu.cn/raspberrypi/ buster main ui
替换后，更新源：
sudo apt-get update更新后，更新已安装包：
sudo apt-get upgrade安装过程中如果碰到(Y/n)，都选择Y