Abstract: For problems of frequent IGBT faults of inverter and motor whistling when mine-used high-voltage inverter supplies power for a long distance, causes were analyzed which were high-voltage inverter's working characteristic causing output waveform to contain high order harmonics and long-distance power supply transmission. A design scheme of output filter of mine-used high-voltage inverter for long-distance power supply was proposed according to output waveform characteristics of inverter. Parameter calculation methods of electric reactor and capacitance in the filter were introduced. The simulation result show that voltage waveform at motor side is smooth without voltage spikes and peaks when the filter is installed at side of mine-used high-voltage inverter for long-distance power supply. Prototype test results show that higher harmonics at motor side are eliminated when the filter is installed, and total harmonics distortion is less than 5%.