Windows+R，输入cmd打开命令行
在命令行中输入pip install pyinstaller
运行命令之后如果安装成功那么会出现：Successfully installed pyinstaller-x.x.x
如果报错：WARNING: You are using pip version 20.1.1; however, version 20.2.3 is available.
解决方法：使用 python -m pip install -U --force-reinstall pip 升级成功
然后就会出现安装成功的提示：Successfully installed pyinstaller-x.x.x
若仍无法安装，那么请参考https://blog.csdn.net/weixin_30483495/article/details/95153992