打开终端工具，拷贝下面的命令粘贴到终端里面按回车键运行安装：

xcode-select --install

如果你已经安装过 Command Line Tools ，运行上面的命令后终端会如下图提示：

xcode-select: error: command line tools are already installed, use "Software Update" in System Settings to install updates