In order to obtain the performance attenuation characteristics of the fuel cell air compressor and im-rove its service life， the durability test for a self-developed fuel cell air compressor was carried out. Combined with the actual road cycle characteristics of fuel cell vehicles， an air compressor life test condition close to the real road cycle was constructed. On this basis， the durability test of the air compressor was carried out for 4 000 hours， and the performance and operation parameters of the air compressor in different running-in periods were collected. Through the analysis of durability test data， the attenuation law of the air compressor performance and its influencing factors were clarified. In addition to running-in time， the performance attenuation of the air compressor is mainly affected by speed and pressure， where the pressure attenuation becomes larger with the increase of speed， the attenuation rate increases first and then slows down with the running-in time， the attenuation of airflow is sensitive to both speed and pressure， and the attenuation rate remains unchanged with running-in time. After 4 000 hours of running-in， the maximum attenuation of air compressor outlet pressure and airflow reaches 7.5% and 29.7%， respectively， at rated operating conditions. The above results provide data basis and reference for the optimization of reliability and design of accelerated endurance conditions for the air compressor.