本人使用的IDEA版本是2019版本，系統是Ubuntu16.04LTS。不過這個應該和啟動閃退的關系不大。其他系統如macOS遇到無法啟動的問題，也可以使用下面的方法步驟。
1.找到IDEA的安裝目錄
我的安裝目錄在：/home/software/idea-IU-193.5662.53 下，這個具體視系統不同可能位置有所差異
2.進入系統的啟動命令目錄
cd /bin 后可以看到有個 idea.sh的shell腳本。在這里執行該腳本。命令 ./idea.sh
我的這里執行后，提示如下內容：
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release. Error occurred during initialization of VM Initial heap size set to a larger value than the maximum heap size
通過報錯可以看出來是IDEA啟動的對堆內存大小設置問題。可能是之前自己設置過值，導致退出IDEA后無法啟動了。
3.返回上一目錄，找到IDEA的具體安裝信息
我這里的安裝配置文件是：Install-Linux-tar.txt，打開后可以看到具體的安裝路徑，在下面的文件內標紅的部分，也就是 ~/.IntelliJIdea2019.3/config
IntelliJ IDEA
INSTALLATION INSTRUCTIONS
===============================================================================
Linux Installation Instructions
------------------------------------------------------------------------------
1. Unpack the IntelliJ IDEA distribution archive that you downloaded to
where you wish to install the program. We will refer to this destination
location as your {installation home} below.
2. Open a console and cd into "{installation home}/bin" and type:
./idea.sh
to start the application. As a side effect, this will initialize various
configuration files in the ~/.IntelliJIdea2019.3 directory.
3. [OPTIONAL] Add "{installation home}/bin" to your PATH environment
variable so that you may start IntelliJ IDEA from any directory.
4. [OPTIONAL] To adjust the value of the JVM heap size, create
~/.IntelliJIdea2019.3/config/idea.vmoptions (or idea64.vmoptions
if using a 64-bit JDK), and set the -Xms and -Xmx parameters. To see how
to do this, you can reference the vmoptions file under
"{installation home}/bin" as a model.
[OPTIONAL] Changing the location of "config" and "system" directories
------------------------------------------------------------------------------
By default, IntelliJ IDEA stores all your settings under the ~/.IntelliJIdea2019.3/config
directory and uses ~/.IntelliJIdea2019.3/system as a data cache.
If you want to change these settings,
1. Open a console and cd into ~/.IntelliJIdea2019.3/config
2. Create the file "idea.properties" and open it in an editor. Set the
idea.system.path and/or idea.config.path variables as desired, for
example:
idea.system.path=~/custom/system
idea.config.path=~/custom/config
3. Note that we recommend to store data cache ("system" directory) on a disk
with at least 1GB of free space.
Enjoy!
-IntelliJ IDEA Development Team
然后cd到 ~/.IntelliJIdea2019.3/config 目錄下，調整idea64.vmoptions的-Xms(最小堆內存:一般設置為256m)與-Xmx（最大堆內存，一般設置為512m）的值即可
最終問題解決