The electromagnetic water make-up valve used in the existing domestic emulsion pump station has low rated working pressure and small flow,which can not meet the use requirements of the existing large mining height fully mechanized mining face.The lever principle and pilot hydraulic control principle were used to optimize the valve design,to solve the problems of small electromagnet thrust and short stroke,so that it could adapt to the working condition of large flow and had higher reliability.In addition,modular design was adopted for the water make-up valve,so one of its components could be changed according to the needs of the actual situation so as to change the pressure and flow of the main valve.It has better practicability.