No negative pressure water supply equipment inlet pipe and water pipe network directly connected to the water pressure in the water pipe network drive under the pressure of surplus equipment into the inlet, the inlet pressure pump equipment on the basis of residual pressure continues to pressurize the water pressure to improve After the pressure required by users to the outlet pipe network water; when the user water is greater than the amount of water supply pipe network, the inlet pipe network pressure drop, when the device inlet pressure falls below the absolute pressure is less than 0 (or set of pipe network protectionist pressures), the device of the negative pressure prevention and control device automatically starts to work on the equipment operating status to be adjusted until the equipment downtime standby to ensure that the inlet pipe network pressure is no longer decreasing the water pipe network adversely affected; when the water pipe ability to restore the water supply network, the inlet pipe network pressure to return to protectionist pressures above, the device automatically starts to restore normal water supply; residual pressure when the water pipe network of water supply to meet user requirements, the device automatically enters sleep mode, the water pipe network directly to the user water supply, inadequate water supply device to automatically resume operation; when users do not use water or water is very small, the device automatically enters hibernation shutdown by the water in the device side of the small flow regulator pressure holding tank to maintain the number of users leaking water pipe network, user water tank holding pressure regulator can not maintain the required pressure water supply pipe network, the device automatically wake up and resume normal operation. Make full use of the device during the operation of the residual pressure water pipe network, neither the water pipe network is always adversely affected and satisfy customer needs, reduce water consumption, water supply system to achieve optimal operation.