The invention relates to a water passing structure, which comprises a water connector, a main rod, a hose and a support pipe. One end of the hose is connected with the water connector, the other end of the hose extends from the lower end of a main rod into a flow passage in the main rod, the hose is arranged in a pipe cavity of the flow passage and provided with a support pipe in the water flow direction, and the outer pipe wall of the support pipe is closely attached to the inner pipe wall of the hose. The invention discloses an ultrasonic scaler handle including the water passing structure.The ultrasonic scaler handle has the beneficial effects that the water connector, the hose and the support pipe are adopted to replace traditional metal connectors, and the assembly is carried out through the method, so that only the hose is used as the water passage outside the position of the coordination of the hose and the support pipe, the hose is relatively soft compared with metal, so as toreduce the damping of the power of an energy converter, and at the same time, the problem of hand shaking through resonance vibration of a shell and the energy converter is overcome.