An active film-discharging device, the film-discharging frame mechanism is connected with the frame through a supporting plate, a braking device is connected on the left end of the reel shaft, the pendulum lever mechanism is connected to the base of the frame through a bearing seat, and the technical punching device is supported by the triangle. The seat is connected to the middle beam of the frame, and a film change film connecting mechanism is arranged on the right side of the middle beam of the frame, a film driving roller mechanism is connected on the left inner side of the frame, and an electromagnetic clutch and a motor are arranged on one end of the rubber roller. The speed reducer is connected; a film forming folding mechanism is arranged on the right side of the upper beam of the frame, and the film forming folding mechanism is provided with a bag film folding depth adjusting rod at the right end, a bag film width adjusting locking seat at the left end, and a bag film under the adjusting rod. The folding plate is formed and a moving connecting rod is arranged in the middle through the bag film width adjusting lock seat. It is suitable for the packaging of large-capacity packaging bags and self-supporting bags, and it is used with horizontal self-supporting bag automatic packaging machines with long distance from the release film to the drawing bag.