A household tooth washing device consisting of a water storage tank A, a handle C, a reverse-flow guard D, a nozzle E, an adjustable spray nozzle F, a small water-blocking guard G, a large water-blocking guard Y, and other components, for resolving the defects of current tooth washing devices, in which water enters the oral cavity but cannot timely exit the oral cavity, and water splashes out of the mouth upon washing the teeth； moreover, a water stream can only be adjusted in the up and down direction by turning the handle by the arm, and it is almost impossible to adjust the same to the left and right. The structure of the water storage tank A of the invention utilizes the principle of negative pressure to realize automatic suction of oral dirty water. The handle of the tooth washing device has a dirty water pipe, which enters the mouth with the handle. The reverse-flow guard prevents water splashing outside the mouth. The nozzles can fine-tune the vertical and horizontal directions of the water stream and can control to output water as a single stream or multiple streams. A small water-blocking guard is provided on the handle to prevent a small amount of water droplets from dripping along the handle. A large water-blocking guard is worn on the fingers or on the palm of the hand and used with the handle to collect water splashes. The components together provide the full functionality of the household tooth washing device.
