A vertically hand palm pressing suction device for a piston breast pump comprises a casing (3) and a piston suction member. The device is provided with a pressing handle (1), which goes through the casing (3) and is fixedly connected with a gear shaft (5) mounted on a base (4). A piston (19) of the piston suction member is connected with a toothed rack (17). The pressing handle (1) and the toothed rack (17) are in transmission connection through a gear member, and the transmission connection converts up-and-down movement of the pressing handle (1) into forth-and-back movement of the piston (19).
