Abstract: Among 70 spacecraft launched,on-orbit faults of ion electric propulsion occurred on 13 of them,with a total of 29 faults in ion electric propulsion's product units.Important engineering experience for ion electric propulsion applied to spacecraft can be obtained based on statistical analysis of these faults.In this paper,on-orbit faults of ion electric propulsions are statistically analyzed,including statistical analysis of their effects on spacecraft and ion electric propulsion systems,and statistical analysis of their time distribution.