In this paper, the mechanism of electrostatic discharge induced by a strong electromagnetic field was studied through software simulation and test verification. By focusing on the effect mechanism of coupling voltage between metal electrodes to induce electrostatic discharge, we obtained the law of electrostatic discharge induced by the strong electromagnetic field. In the process of electrostatic discharge induced by the strong electromagnetic field, due to the antenna receiving effect of metal electrode structure, the strong electromagnetic field would form coupling induction voltage on the metal electrode. The voltage acts on both ends of the discharge electrode structure and generates an electric field in the gap between the electrode structure, which superimposes on the original field; furthermore, it has an impact on the electrostatic discharge process, resulting in the formation of induced discharge with low charging voltage structure.