One kind of impacting damper design method has been proposed to solve the problem of high pressure sensor damage rate and pressure testing data distortion in the process of high pressure motor pressure test. Through reasonable designing of parameters such as bend pipe bending Angle and radius of curvature, the high temperature and high pressure airflow has been forced to turn to weaken the shock wave energy, accordingly pressure sensor can be protected and the pressure can be effectively measured. The results show that, the problem of pressure sensor damage can be solved and the test precision can be ensured by this pressure test method.