Punching mechanism capable of automatically discharging waste

The utility model relates to the technical field of leather punching machines, and particularly discloses an automatic waste discharging punching mechanism which comprises a punching unit and a first plate body used for bearing the punching unit. The punching unit comprises a punching knife used for punching an external material, a connecting piece provided with the punching knife and a first driving piece used in cooperation with the punching knife, and the first driving piece is used for driving the punching knife to do reciprocating motion through the connecting piece; a center hole penetrating through the stamping knife is formed in the stamping knife, a first pneumatic hole and a waste material hole are further formed in the connecting piece, the first pneumatic hole is communicated with the center hole and the waste material hole so that waste materials in the center hole can be discharged through the waste material hole, the through center hole is formed in the stamping knife, the waste material hole i