一、系统参数设置:
1.64位IDEA:增加IDEA_JDK_64系统变量
2.32位IDEA:增加IDEA_JKD系统变量
如图:

二、参考说明
https://intellij-support.jetbrains.com/hc/en-us/articles/206544879-Selecting-the-JDK-version-the-IDE-will-run-under
详情如下:
<product>.exe uses this JDK search sequence:
-
IDEA_JDK / PHPSTORM_JDK / WEBIDE_JDK / PYCHARM_JDK / RUBYMINE_JDK /CLION_JDK / DATAGRIP_JDK environment variable (depends on the product,WEBIDE_JDK applies to both WebStorm and PhpStorm before version 2016.1)
- ..\jre directory
- system Registry
- JDK_HOME environment variable
- JAVA_HOME environment variable
idea64.exe uses this JDK search sequence:
- IDEA_JDK_64 environment variable
- ..\jre64 directory
- system Registry
- JDK_HOME environment variable
- JAVA_HOME environment variable
It’s also possible to start the IDE with <product>.bat file located in the bin directory, it uses the following JDK search sequence:
- IDEA_JDK / PHPSTORM_JDK / WEBIDE_JDK / PYCHARM_JDK / RUBYMINE_JDK/ CLION_JDK / DATAGRIP_JDK environment variable (depends on the product)
- ..\jre directory
- JDK_HOME environment variable
- JAVA_HOME environment variable
Environment variable must point to the JDK installation home directory, for example:
c:\Program Files (x86)\Java\jdk1.8.0_66
- The actual JDK version used by the IDE can be verified in Help | About dialog (open any project to access the menu).
- Define IDEA_JDK / PHPSTORM_JDK / WEBIDE_JDK / PYCHARM_JDK / RUBYMINE_JDK / CLION_JDK / DATAGRIP_JDK variable depending on the product to override the default version from IDE_HOME\jre.
- Use Rapid Environment Editor to add/edit the variables, it will detect incorrect paths.
给IDEA设置单独的JDK
原文:http://www.cnblogs.com/scown/p/5561625.html