The utility model discloses a punching machine. A side fixed seat is fixed on a base, a sliding rod is vertically fixed on the side fixed seat, a motor is slidably arranged on the sliding rod, the sliding rod is sleeved with a spring A, two ends of the spring A are respectively connected with the motor and the base, a drill bit is connected with an output shaft of the motor, a pressing rod is rotatably fixed on the side fixed seat through a rotating shaft, a pressing shaft is rotatably fixed on the side of the motor and provided with a through hole, the pressing rod penetrates the through hole, the center of a poking disc is provided with a threaded hole, the poking disc is horizontally arranged in the base, part of the outer circumference of the poking disc is protruded out of the base, a lifting screw is in threaded fit with the threaded hole of the poking disc and is connected with a lifting table above the base, and the lifting table is located under the drill bit. The punching machine has the advantage that when the punching machine suitable for a U-shaped connecting piece performs punching on the U-shaped connecting piece, the distance between the two sides of the U-shaped connecting piece is not changed.