下载安装mingw-get-setup.exe：
https://osdn.net/projects/mingw/releases/
或直接下载:https://osdn.net/projects/mingw/downloads/68260/mingw-get-setup.exe/
安装成功后在C:\MinGW\bin下有mingw-get.exe，也可将其加入到环境变量.
现在开始安装gcc
C:\MinGW\bin>mingw-get.exe install gcc
gcc已经成功安装，接下来将gcc加入到环境变量即可