Hi @Bing Wang,
That SSIS OS service is not needed at all starting from SSIS 2012 onwards.
It is kept for backward compatibility with the obsolete SSIS circa 2005 - 2008R2 era.
For the reference:
The topics in this section discuss the Integration Services service, a Windows service for managing Integration Services packages. This service is not required to create, save, and run Integration Services packages. SQL Server 2012 (11.x) supports the Integration Services service for backward compatibility with earlier releases of Integration Services.