Non-negative pressure water supply equipment is a new type of pressurized water supply equipment launched in recent years. This equipment can be directly connected to the pipe network of running water. It supplies water at constant pressure by fully utilizing the original water supply pressure of running water and by controlling working water pumps through advanced variable-frequency speed regulation technology. One characteristics of the equipment is that it utilizes the original pressure of pipe network to achieve efficiency and energy conservation. Furthermore, negative pressure suppression technology is adopted to prevent occurrence of negative pressure during operation, thus safeguarding the safety of pipe network of running water. First, the working pressure of water use site is set based on actual conditions and the pressure of municipal pipe network is constantly monitored. When the pressure is lower than the pressure demanded by users, the micro automatic control frequency converter will be started to increase the rotation speed of water pump until the pressure of pipe network is raised to the pressure demanded by users and the water pump is controlled to operate at constant rotation speed to ensure water supply at constant pressure. When the water consumption is increased, the rotation speed will increase accordingly; when the water consumption is decreased, the rotation speed will also decrease accordingly. In this way, the pressure of water supply to users is maintained at a constant pressure. The lower the pressure of running water, the higher the rotation speed of the water pump; the higher the pressure of running water, the lower the rotation speed of the water pump. When the pressure of running water is not lower than the pressure demanded by users, the water pump will stop running. During operation, the equipment will fully utilize the original pressure of running water and keep water supply at constant pressure. During operation of the equipment, the microcomputer will constantly monitor the pressure of both municipal pipe network and the system and automatically control the vacuum suppressor and steady current compensator to restrain the occurrence of negative pressure. In this way, it not only fully utilizes the pressure of municipal pipe network but also prevents the occurrence of negative pressure. Therefore, it does not cause any adverse effect to municipal pipe network and ensures the safety of water use. This non-negative pressure water supply equipment not only utilizes the original pressure of pipe network of running water but also sufficient storage water to meeting the demand for water supply at peek time. Furthermore, it does not produce suction to the pipe network of running water.