Phenomenon of electrostatic hazards is becoming increasingly prominent with wide application of microelectronic elements. Electrostatic Discharge (ESD) is an extremely complex process, which is not only related to the materials, the object shape and the value of discharging circuit resistance, but also always involved in very complicated process of gas breakdown, so ESD is also a stochastic process which is difficult to repeat. According to the request of standard IEC61000-4-2, simulation circuit of the equivalent Human-Metal Model is established, discharging process is simulated and analyzed, and the influence laws of circuit parameters and distribution parameters for ESD current waveform are obtained. Thus the structure of discharging circuit and element parameters can be determined, test results can be verified to some extent, and the characteristics and influencing factors of ESD process can be known better. Simulation results show that waveform parameters are all within the range of standard errors, which proves that the design of model parameters is correct, the analysis of ESD process is reasonable.