In the present paper, characters of the electromagnetic valves currently for sailare analysed and the factors affecting vibration frequency of the valves is dis-covered. A new valve design is proposed by shortening stroke distance of the valve,altering motion condition im magnetic field and picking a magnetic saturated alloyof iron and nickel as the material for the valve.The testing result shows that thevalve is characterized by high frequency. Its working frequencies range from 290to 330 times per second, which meet the requirement for a photoelectric tea grader.