先进入到applications文件夹下：
cd /usr/share/applications
然后：
sudo gedit idea.desktop
粘贴内容：
[Desktop Entry]
Encoding=UTF-8
Version=1.0
Name=IntelliJ IDEA
GenericName=Java IDE
Comment=IntelliJ IDEA is a code-centric IDE focused on developer productivity. The editor deeply understands your code and knows its way around the codebase, makes great suggestions right when you need them, and is always ready to help you shape your code.
Exec=/usr/local/lib/idea/bin/idea.sh
Icon=/usr/local/lib/idea/bin/idea.png
Terminal=false
Type=Application
Categories=Development;IDE
红色部分对应的是你的idea.sh文件的地址，然后保存即可。