In order to solve the problem of high-amplitude and high-frequency interference generated by the electric drive system of new energy vehicles, the author proposes a closed-loop research method for on-load electromagnetic compatibility testing and simulation for electric drive systems of new energy vehicles. The method includes EMC design of the electric drive system on-load test equipment, establishment of a conducted EMI simulation platform for the electric drive system under load conditions, and optimization of the conducted EMI performance of the electric drive system based on key parameters and PWM control. Experimental results show that if the parasitic inductance of the IGBT gate increases, the conducted emission level in the frequency range of 2∼30 MHz will increase, and there is basically no change at the low frequency, and the position of each resonance point shifts to the relatively low frequency. The experiment was replaced with the DPWM3 modulation mode, and the conducted emission amplitude was reduced by about 2 dBμV in the range of 200 kHz∼2 MHz, and there was basically no change on the whole. Conclusion. It is proved that the electromagnetic compatibility closed-loop development technology of the electric drive system of new energy vehicles under load conditions can meet the development needs of new energy vehicles in the environment where energy problems and air pollution problems are becoming more and more serious.