Abstract: Abstract: It is comprehensively introduced that the design characteristics, versatility, efficiency and output power quality, reliability and maximum availability, etc. of the cell-series multi-level medium-voltage converter, and the advantages and development trend of the inverter is illustrated. Through the application in the large belt conveyor of main inclined shafts in the mines with 10Mt capacity at datong coal mine group, the function and advantage of variable frequency drives in the belt conveyor has been introduced, and the importance and necessity of localization and coal mine customization of the converter is illustrated. Furthermore the future development trend of the variable frequency drives on the application in the belt conveyors is pointed out, and indicates the role and significance for coal mine development.