Abstract: Generation mechanism of EMI in high-power explosion-proof inverter was analyzed, and design method of an EMI filter for high-power explosion-proof inverter was proposed. The EMI filter uses "P" matching network structure based on a single LC filter, and realizes impedance matching of the explosion-proof inverter in the case of impedance mismatching, so as to improve EMI filtering effect. A 1 MW/1 140 V explosion-proof inverter was tested to verify validity of the EMI filter.