The invention discloses an automatic water feeding and draining system which comprises a SPA cylinder and a master controller, wherein a nozzle is arranged in the SPA cylinder; an infrared emitter and an infrared receiver are arranged on the upper side of the SPA cylinder; a water draining pipe and a water return pipe are connected with the bottom end of the SPA cylinder; a water feeding pipe is connected with the side wall of the SPA cylinder; a filter cartridge is arranged in the water feeding pipe; the water return pipe and the water feeding pipe are connected with a water pump through a main pipe; the main pipe is connected with a water replenishing pipe through a three-way valve. According to the system, the design of infrared monitoring in match with automatic water replenishing is adopted according to the requirement of maintaining constant water level in SPA massage pool for guaranteeing use effect, so that the trouble in manual control on water replenishing is avoided.