Slow-closing check valve is an intelligent valve installed at the pump outlet of water supply system and other water supply systems in high-rise buildings to prevent medium backflow, water hammer and water hammer. It has three functions: electric valve, check valve and water hammer eliminator. It can effectively improve the safety and reliability of water supply system, and integrate the technical principles of slow-opening, fast-closing and slow-closing to eliminate water hammer. To prevent the occurrence of open and shut-down water hammer, the valve can be automatically opened and closed according to the operation rules of the pump by operating the pump motor's open and close button. The valve has large flow rate and low pressure loss, and is suitable for valves under 600 caliber.