Abstract: Satellite-based augmentation is an important means to support civil aviation route operations and terminal area operations. In order to verify whether the BeiDou Satellite-Based Augmentation System (BDSBAS) complies with the International Civil Aviation Organization (ICAO) signal-in-space performance requirements , to evaluate and analyze it. In this paper, the actual broadcast ephemeris, precise ephemeris and BDSBAS enhanced messages are used as experimental data. The performance of BDSBAS was evaluated and analyzed based on six indicators, point, broadcast time and ionospheric delay error. The results show that the GPS satellite orbit error, satellite clock error and space signal ranging error after BDSBAS enhancement are improved compared with those before enhancement; BDSBAS grid ionospheric effective points cover China and surrounding areas; ionospheric delay broadcast interval reaches ICAO Requirements for precise differential positioning; the ionospheric delay has a large error in the range of 0° to 15°N, and the reliability is poor; in the range of 20°N-55°N, the error is small and the reliability is good.