Full-automatic water-saving flush closet

The utility model discloses an automatic water saving flushing device which comprising a water tank 1, a water inlet pipe 2, a ball float valve 3, a water drain valve 4, an electromagnetic device 5 and a computer-controlled automatic ringer 6; wherein the electromagnetic device 5 is connected with the water drain valve 4 through a draft line. The utility model is mainly applied the toilet flushing for schools, departments and pubic toilets. Because of the adoption of the computer program for controlling flushing, the utility model has the functions of automatic water filling and drainage and can reduce flushing time and the water drainage quantity by 75 percent, achieving the effect of facilitation and saving water source.