Abstract: This paper develops a surface discharge effect simulator for spacecraft, complete with its parameters, principles and design. The accuracy of the discharge voltage is determined by a calibration system. The discharge current pulse characteristics are measured, such as the peak current of the discharge, the rise time of the discharge current, and the pulse width of the discharge current. The relations between the discharge current pulse characteristics and the discharge voltage are analyzed. It is shown that the discharge characteristics of the simulator can meet the requirements of the surface discharge effect simulating test for spacecraft.