Water pump mechanism, oral irrigator main machine and oral irrigator

The utility model discloses a water pump mechanism, a water pick main machine and a water pick, and relates to the technical field of oral cavity cleaning. The water pump mechanism comprises a driving piece, a piston and a cylinder body; the cylinder body comprises a first end and a second end which are opposite to each other, the second end is located below the gravity direction of the first end, the cylinder body further comprises a cone part, and the cone part is arranged at the second end; vertical to the gravity direction, the cross section area of the cone part close to the first end is larger than the cross section area of the cone part far away from the first end; the piston is installed in the cylinder body in a sliding mode, and the piston is arranged close to the first end. The driving piece is located on the side, away from the second end, of the first end, and the driving piece is in transmission connection with the piston. According to the water pump mechanism, the possibility that the driving p