Leakage-proof plunger type toothwash pump

The plunger type tooth washing pump comprises a pump body and a motor, the pump body is provided with a piston cavity, a liquid inlet flow channel and a liquid outlet flow channel, the liquid inlet flow channel and the liquid outlet flow channel are communicated with the piston cavity, a liquid inlet one-way valve and a liquid outlet one-way valve are arranged in the liquid inlet flow channel and the liquid outlet flow channel respectively, and a plunger is arranged in the piston cavity and connected with the output end of the motor through a linkage mechanism. The plunger is sleeved with a sealing piece, an extension protruding part abutting against the side wall of the piston cavity is formed on the peripheral wall of the lower end of the sealing piece, a liquid storage groove is formed in the sealing piece, an upper flange abutting against the side wall of the piston cavity is formed in the circumferential direction of the liquid storage groove, and the contact area of the upper flange and the side wall of