The invention relates to the field of punching equipment, and discloses an automatic punching machine. The automatic punching machine comprises a machine body, a core mold which can be inserted into ato-be-punched pipe so as to support the to-be-punched pipe in the radial direction, a clamp capable of clamping the to-be-punched pipe and punching mechanisms, the automatic punching machine comprises the plurality of punching mechanisms, wherein each punching mechanism comprises a punching head, punching holes corresponding to the punching heads are formed in the outer peripheral surface of thecore mold, the punching mechanisms can drive the punching heads to move towards the core mold in the radial direction so as to enable the punching heads to be inserted into the punching holes, the automatic punching machine is further provided with a clearing mechanism used for clearing residual wastes in the punching holes, and the other end of the core mold is provided with a grinding head capable of grinding the inner wall of the pipe. By clamping the pipe at a time, multiple kinds of hole patterns of different positions of the pipe can be punched, meanwhile, the wastes punched out of the core mold can be cleared, and burrs on the inner wall of the pipe can be ground.