Abstract: Strong electromagnetic pulse can be coupled into vehicle engine management system (EMS) through external cables, causing interference and even damage to EMS equipment. Electromagnetic protection components can provide support for vehicle EMS protection design. This article takes vehicle EMS as the research object, comprehensively considers EMS equipment and its external connecting cables, establishes an electromagnetic simulation model of EMS equipment, and conducts simulation research on the port coupling characteristics of cables of different lengths and the induced current on the surface of EMS metal shell. Based on protective circuit simulation, an electromagnetic protection component applied to vehicle EMS equipment was designed. The simulation results show that the protection component can limit the 5 kV electromagnetic pulse to the maximum peak amplitude of 18 V, and the protection efficiency reaches 48 dB. Adding the protection component to the EMS cable interface can effectively improve the reliability in strong electromagnetic environment, which has certain reference significance for the electromagnetic protection design of the vehicle platform control system.