Research was aimed at the problem of BRW200/315 type mine emulsion pump that having big noise and often appearing drain valve cores deformation, even fracture in the running. Through establishing AMESim model of the pump, it was fund by analysis that the impact of drain valve core was the source of the pump noise. Based on the ANSYS Static Structural simulation, the condition of stress and deformation in the operating conditions of the drain valve core were analyzed. By changing the structure parameters of valve core to achieve the purpose of optimization, theoretical basis is provided for manufacturing process.