The assessment of surveillance performance of the Automatic Dependent Surveillance-Broadcast (ADS-B) system is of significant importance for ensuring civil aviation flight safety. Firstly, by referencing the technical specifications of the European Organization for the Safety of Air Navigation, ADS-B surveillance performance indicators and their statistical methods were proposed. Secondly, based on these, an ADS-B surveillance performance assessment system was designed and constructed. Finally, using surveillance data collected from the ADS-B ground station at the Civil Aviation University of China, 16 surveillance performance indicators for the high-altitude air routes surrounding Tianjin Airport have been statistically derived by the study. The study shows that the effective coverage radius of ADS-B ground stations is 170 km, and within the coverage area, the evaluated 16 performance indicators all meet the technical specifications for surveillance performance of high-altitude airways.