The auxiliary gate valve seat is one of the earliest gate valves which is forced to form a sealing force by the hand wheel. The two sealing surfaces of the gate are wedge-shaped with the same degree as the valve seat. The movement direction of the gate is perpendicular to the fluid direction. The wedge with the valve seat can achieve the sealing specific pressure, and the sealing meets the national standard. Copper alloy sealing surface has good corrosion resistance and high temperature resistance. It can be used in the condition that rubber can not be used. It is suitable for fire protection, industrial water system and other water systems. It can be used for connecting or cutting off pipelines, and has the functions of service valve, on-off valve and air vent valve.