引用别人的
https://blog.csdn.net/aqxin/article/details/52441178
1、开启gradle单独的守护进程
在下面的目录下面打开（创建）gradle.properties文件
/home/<username>/.gradle/ (Linux)
/Users/<username>/.gradle/ (Mac)
C:\Users\<username>\.gradle (Windows)
并在文件中增加：
org.gradle.daemon=true
同时修改项目下的gradle.properties文件也可以优化：
# Project-wide Gradle settings.
# IDE (e.g. Android Studio) users:
# Settings specified in this file will override any Gradle settings
# configured through the IDE.
# For more details on how to configure your build environment visit
# http://www.gradle.org/docs/current/userguide/build_environment.html
# The Gradle daemon aims to improve the startup and execution time of Gradle.
# When set to true the Gradle daemon is to run the build.
# TODO: disable daemon on CI, since builds should be clean and reliable on servers
org.gradle.daemon=true
# Specifies the JVM arguments used for the daemon process.
# The setting is particularly useful for tweaking memory settings.
# Default value: -Xmx10248m -XX:MaxPermSize=256m
org.gradle.jvmargs=-Xmx2048m -XX:MaxPermSize=512m -XX:+HeapDumpOnOutOfMemoryError -Dfile.encoding=UTF-8
# When configured, Gradle will run in incubating parallel mode.
# This option should only be used with decoupled projects. More details, visit
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
org.gradle.parallel=true
# Enables new incubating mode that makes Gradle selective when configuring projects.
# Only relevant projects are configured which results in faster builds for large multi-projects.
# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:configuration_on_demand
org.gradle.configureondemand=true
同时上面的这些参数也可以配置到前面的用户目录下的gradle.properties文件里，那样就不是针对一个项目生效，而是针对所有项目生效。
上面的配置文件主要就是做， 增大gradle运行的java虚拟机的大小，让gradle在编译的时候使用独立进程，让gradle可以平行的运行。
2、让Android studio可以申请大内存
installation path\bin\studio64.exe.vmoptions or studio.exe.vmoptions
使用文本编辑器打开，找到起始两行，如下
-Xms128m
-Xmx750m
修改最小值和最大值，建议为
-Xms256m
-Xmx2048m
3、Android Studio启动优化
installation path\bin\idea.properties
使用文本编辑器打开，在最末添加一行
disable.android.first.run=true
4、优化编译
打开设置页面 File->Settings->Build->Compiler
勾选除第二项之外的其他选项，开启优化
打开设置页面 File->Settings->Build->Build Tools->Gradle
勾上“Offine work”选项，勾上后就不会联网进行第三方库的自动下载。
注：每次升级Android Studio或SDK后这些配置有可能会恢复默认
