Abstract: Electric control system of main hoister of the fifth coal mine of Pingdingshan Mining Group adopted relay-contactor control method,which was backward and serious aging, needed to be reformed immediately. According to the characteristics of the coal mine, the paper provided three reforming methods and analyzed the advantages and shortcomings of the reforming methods, gave the best reforming method for the coal mine. It also analyzed several important segments of reforming of networked control system.