The ignition system in automobiles is a main source of electromagnetic interference (EMI), because the electromagnetic emission from the system has the characteristics of high-energy and wide-bandwidth. A method for EMI prediction based on its components’ circuit models is presented. First, the characteristics of the components are analyzed and the equivalent circuits are drew; then, the parasitic parameters of the electromagnetic device are extracted from measurement, analytical solution or finite element method (FEM); and finally, the circuit model of the whole ignition system model in high frequency condition is established. This model is verified by the measurement and simulation results in time domain and in frequency domain.