To study the Electromagnetic Interference （EMI） characteristics of the Fuel Cell Controller （FCU）， this paper develops an equivalent radiation source using the differential evolution algorithm and measures the magnetic field of the FCU controller based on the near-field scanning method. By comparing the magnetic field generated by the equivalent radiation source with the measurement， the average error in X， Y， and Z direction at each frequency point is about 3%. Then， the far-field radiation in the half-space above the PCB board is simulated with the reconstructed model， and the results show that the average error between the simulated electric field and the measured electric field is around 4.1 dB， and the overall trend tends to be consistent in the measurement band range， which shows the accuracy of the equivalent radiation source reconstructed based on differential evolution algorithm. Thus， this method can be used for predicting the effects of the radiation sources. Furthermore， this paper also investigates the effect of the metal shell based on the reconstructed equivalent radiation source， and the results show that far-field radiation of the PCB board is reduced by about 10 dB. Thus， the metal shell can effectively reduce the radiation interference generated by the FCU controller.