The water meter check valve only allows water in the water pipe to flow in one direction. When fluid pressure acts in the same direction, the valve disc will open; If the fluid flows in the opposite direction, the valve disc will automatically overlap, cutting off the flow of water and preventing the backflow of tap water. Installing a check valve in front of the water meter can effectively prevent damage to the water meter due to backflow, especially to prevent the backflow phenomenon from causing damage to the internal structure of the water meter, thereby affecting its normal measuring function.