下载flutter SDK

1.去flutter官网下载其最新可用的安装包

2.解压安装包到你想安装的目录，如：

cd ~/development
unzip ~/Downloads/flutter_macos_v0.5.1-beta.zip

3.添加flutter相关工具到path中：

export PATH=`pwd`/flutter/bin:$PATH

Mac系统下的环境变量：

文件	作用
/etc/profile	系统级别，系统启动加载
/etc/paths	系统级别，系统启动加载
~/.bash_profile	用户级别，优先读取（建议配置）
~/.zshrc	zsh 用户，效果等同于 bash_profile
~/.bash_login	用户级别，次优先读取（有profile则不读取）
~/.profile	用户级别，次次优先读取（有profile/login则不读取）
~/.bashrc	bash shell打开的时候载入

测试flutter

flutter --version --verbose
[  +10 ms] executing: [/Users/xxx/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%H
[  +34 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%H
[        ] 8af6b2f038c1172e61d418869363a28dffec3cb4
[        ] executing: [/Users/xxx/flutter/] git tag --contains HEAD
[ +165 ms] Exit code 0 from: git tag --contains HEAD
[   +2 ms] 1.17.5
[   +6 ms] executing: [/Users/xxx/flutter/] git rev-parse --abbrev-ref --symbolic @{u}
[   +8 ms] Exit code 128 from: git rev-parse --abbrev-ref --symbolic @{u}
[        ] fatal: HEAD does not point to a branch
[  +10 ms] Unable to locate an Android SDK.
[  +21 ms] executing: [/Users/xxx/flutter/] git rev-parse --abbrev-ref HEAD
[   +9 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] HEAD
[   +1 ms] executing: [/Users/xxx/flutter/] git rev-parse --abbrev-ref HEAD
[   +8 ms] Exit code 0 from: git rev-parse --abbrev-ref HEAD
[        ] HEAD
[        ] executing: [/Users/xxx/flutter/] git fetch https://github.com/flutter/flutter.git --tags
[+187014 ms] Exit code 0 from: git fetch https://github.com/flutter/flutter.git --tags
[        ] From https://github.com/flutter/flutter
            * branch                  HEAD       -> FETCH_HEAD
[        ] executing: [/Users/xxx/flutter/] git tag --contains HEAD
[ +166 ms] Exit code 0 from: git tag --contains HEAD
[        ] 1.17.5
[        ] executing: [/Users/xxx/flutter/] git -c log.showSignature=false log -n 1 --pretty=format:%ar
[   +9 ms] Exit code 0 from: git -c log.showSignature=false log -n 1 --pretty=format:%ar
[        ] 5 months ago
[  +14 ms] Flutter 1.17.5 • channel unknown • unknown source
           Framework • revision 8af6b2f038 (5 months ago) • 2020-06-30 12:53:55 -0700
           Engine • revision ee76268252
           Tools • Dart 2.8.4

注意选择对应的channel 和 version

环境配置问题，都能通过百度，谷歌解决

ruby
cocoapods
rvm
....

参考文档

https://flutterchina.club/setup-macos/