Abstract: 10 cm diameter divergent magnetic field ion thruster is developed by Lanzhou Institute of Physics for the ultra-low orbit monitoring satellites.In order to verify whether the working performance of the thruster meets the requirements of in-orbit task,a series of ground test including performance test and environmental test have been carried out.The test results show that the base frequency of three orthogonal directions of the 10 cm diameter ion thruster are 601 Hz,583 Hz and 736 Hz,respectively,and the thruster has no abnormalities after the impact test of 1 600g magnitude;after mechanical test and thermal vacuum test of 25.5 cycles,the working performance of the thruster is basically unchanged.The full divergence angle in every work conditions of the thruster are all within 30°,then the maximum thrust deflection angle is less than 1°,and the ratio of double charged ions is 14.1% in 20 mN work condition.The overall error of thrust value based on electrical parameter measurement method is less than 0.95 and all are within the required range.The ground test proved that the performance of the domestic 10 cm diameter divergent magnetic field ion thruster meets the requirements of the ultra-low orbit monitoring satellites.