With the arrival of large aircraft such as C919,test system puts forward higher technical requirements for airborne real-time processing system. The real-time processing system of airborne network data adopts vxWorks development environment with strong real-time. Through allocates of resources rationally between the functional modules, that is, allocates of threads rationally to complete all functional modules real-time. Verified by scientific research in flight test, the system has real-time processing capability of 3 000 parameters. The system is stable and extensible, and meets the requirements of real-time data processing tasks for large aircraft airborne test system. It has positive significance for ensuring the smooth going of subjects test for large aircraft.