Abstract: The fully-mechanized mining face in Tongxin Mine is equipped with the negative pressure secondary dust suppression system, which causes problems such as frequent faults of spray pump, unreliable automatic water supply system and serious nozzle blockage. Through the transformation of negative pressure secondary dust suppression system, the 3SP60-15/4.8 high-pressure pump is used as the power source of negative pressure spray dust suppression, and the intelligent automatic water replenishment of high-pressure spray pump is realized through the transformation of automatic water replenishment system, and the spray distance sector is up to standard through the transformation of dust catcher nozzle. The application of the three technical transformations has solved the problems of water source power, automatic water replenishment and spray coverage area of the spray system of shearer, which realizes the continuous operation of the equipment, greatly improves the working environment of the whole working face, and avoids the occupational health harm of dust to the workers.