Lhasa Kongga International Airport is located in the Yarlung Zangbo River valley, with an elevation of 3,569 meters. The surrounding mountains are numerous, and the meteorological environment is complex and changeable, which has high requirements for the plateau operation performance of aircraft. Flying to Lhasa this time, the C919 aircraft will carry out development flight tests of systems critical to high plateau operation, such as the environmental control system, the avionics system and the power plant system, as well as high plateau airport adaptability checks, thus to lay a foundation for subsequently meeting the operational requirements of high plateau routes and the development of plateau versions of aircraft.