The emulsion pump station is the power source of hydraulic supports and hydraulic props of coal mine fully mechanized coal mining face, which provides working medium with high pressure and large flow rate for hydraulic system. The pressure control system of emulsion pump station based on electrohydraulic proportional relief valve was designed. By using electrohydraulic proportional relief valve technology,and using PID controller to perform logical operations in the PLC control system, the pressure unloading of the valve was controlled. The control system was designed in detail, the mathematical model of the system was established, and the control effect was analyzed by simulation.