1 先去下载flutter SDK ：SDK下载地址
2 在终端输入以下指令

vi $HOME/.bash_profile

export PUB_HOSTED_URL=https://pub.flutter-io.cn //国内用户需要设置
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn //国内用户需要设置
export PATH=PATH_TO_FLUTTER_GIT_DIRECTORY/flutter/bin:$PATH

注意：PATH_TO_FLUTTER_GIT_DIRECTORY 为你flutter上级文件夹的路径，比如“~/document/code”

 export PATH=~/document/code/flutter/bin:$PATH

刷新当前终端窗口，输入下面指令

source $HOME/.bash_profile 

注意: 如果你使用的是zsh，终端启动时 ~/.bash_profile 将不会被加载，解决办法就是修改 ~/.zshrc ，在其中添加：source ~/.bash_profile
通过运行flutter/bin命令验证目录是否在已经在PATH中:

echo $PATH

运行 flutter doctor

flutter doctor

成功的例子如下图

成功图片

常见问题：
安装flutter 出现的问题;

iOS toolchain - develop for iOS devices (Xcode 10.0)

libimobiledevice and ideviceinstaller are not installed. To install with

Brew, run:

brew update

brew install --HEAD usbmuxd

brew link usbmuxd

brew install --HEAD libimobiledevice

brew install ideviceinstaller

ios-deploy not installed. To install with Brew:

brew install ios-deploy

Brew can be used to install tools for iOS device development.

Download brew at [https://brew.sh/.](https://brew.sh/.)

解决方案：先 https://brew.sh/. 去这个网址安装指令， 及时可以使用 brew指令了,提示install xcode ，如果已经安装了xcode，只执行那个指令即可，

brew update

brew install --HEAD usbmuxd

brew link usbmuxd

brew install --HEAD libimobiledevice

brew install ideviceinstaller

brew install ios-deploy

逐步在终端输入这些命令即可

常见问题：

dart SDK 版本过低：更新flutter SDKflutterSDK链接