Abstract: According to the typical electrostatic discharge, namely as electrostatic discharge(ESD), current waveform in IEC 61000-4-2, the current waveform has a variety of fitting and is not easy to realize this problem through specific circuit. The method of solving circuit state equations is used to calculate the four ESD simulator circuits, and four exponential forms of ESD current analytical expression are obtained. The corresponding current curve is drawn. The continuity and conductance of the analytical expression of the ESD current waveform produced by four ESD simulator circuits are discussed respectively. The difference between the ESD current waveform produced by different circuits and the difference between the current waveform of the IEC 61000-4-2 standard and the current waveform of the IEC is compared. The results show that four main current waveforms produced by different ESD circuits are in accordance with the IEC 61000-4-2 standard. However, the continuity and conductance of the current waveforms are different because of the different topology and component parameters of the circuit. Therefore, the actual human parameters and discharge guns should be based on the actual parameters when selecting the ESD model. The parameters determine the appropriate circuit structure. The calculation method is suitable for solving the lumped parameter circuit and provides a new current analytical formula for the simulation and calculation of the ESD electromagnetic pulse radiation field.