Abstract: Electrostatic discharge (ESD) of charged device model (CDM) characterizes the process in which charges accumulate in the device through electrostatic induction and resulting in ESD impact. It is one of the major ESD risks faced in the ground electronical fitting/assembly by spacecraft electronic products. The equivalent circuit model was investigated and designed to analyze the theory together with the process of charge and discharge of ESD of CDM. The proposed model was studied theoretically and experimentally in addition to the simulation to analyze the influence of various parameters on the ESD waveform characteristics. The comparison and verification show that the discharge waveform of the equivalent circuit has a high consistency with the standard waveform. ESD of CDM exhibits an impulse signal with a rising edge of hundreds of picoseconds, a maximum peak current of several amperes, and multiple oscillations in positive/negative cycles. The larger the equivalent capacitance of the device is, the stronger the impact pulse is. The path resistance also significantly changes the waveform of electrostatic impact. In ground operation, the risk of CDM discharge would need to be fully considered, and measures are recommended to be taken to reduce the possible damage to circuits and devices caused by ESD.