Abstract: A direct water typed auto-flushing device for toilets is disclosed. The device includes a flush valve, which guides washing water from a water supply to a bidet tank and an actuating unit, and discharges the washing water into a toilet so as to dispose of excrement therein. A sensor is mounted to the underside of a bidet seat, and determines whether excrement is urine or feces according to a user sensing time. An actuating unit opens a solenoid valve and drains washing water, stored in a pressure chamber of the flush valve, through a drain hose into the toilet, thus disposing of excrement in the toilet using washing water fed from a water supply, according to the result of detection by the sensor. The device simplifies a construction by which washing water is fed through the water supply to the bidet tank and the pressure chamber.