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:

1. 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)

2. ..\jre directory
3. system Registry
4. JDK_HOME environment variable
5. JAVA_HOME environment variable

idea64.exe uses this JDK search sequence:

1. IDEA_JDK_64 environment variable
2. ..\jre64 directory
3. system Registry
4. JDK_HOME environment variable
5. 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:

1. IDEA_JDK / PHPSTORM_JDK / WEBIDE_JDK / PYCHARM_JDK / RUBYMINE_JDK/ CLION_JDK / DATAGRIP_JDK environment variable (depends on the product)
2. ..\jre directory
3. JDK_HOME environment variable
4. 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.