The Ground-Based Augmentation System (GBAS), as an innovative navigation technology, has become increasingly prominent in its outstanding advantages in enhancing airport operational efficiency and ensuring flight safety. Lhasa Gonggar International Airport is taken as a starting point, the basic working principles of GBAS, the selection of ground-station sites, and the methods for performance evaluation are deeply and systematically explained. By analyzing the impact of ionospheric activities on the service performance of GBAS, the applicability of GBAS in high-altitude and low-latitude regions is verified. The research results show that the ionospheric activities in the area of Lhasa Gonggar Airport are in a relatively stable state. The GBAS system can meet the operational standards of Category I precision approaches in terms of accuracy, integrity, and availability. The findings of this study provide crucial reference for the wide application of GBAS in plateau airports and have important practical significance for promoting the in-depth application of satellite-based navigation technology in the civil aviation field of China.