Automatic film cutting device

The utility model belongs to the technical field of agricultural mechanical equipment, and particularly relates to an automatic film cutting device which comprises two pairs of connecting arms, a front cross rod and a rear cross rod, the left ends of the two pairs of connecting arms are fixedly connected with the front cross rod, the right ends of the two pairs of connecting arms are fixedly connected with the rear cross rod, and a supporting arm is vertically and fixedly connected between the two pairs of connecting arms. The lower portion of the rear cross rod is rotationally connected with a film spreading roller, the right surface of the rear cross rod is fixedly connected with two right hinges in a bilateral symmetry mode, the lower hinges of the two hinges are fixedly connected with film cutting blades in a bilateral symmetry mode, extension arms are arranged on the outer surfaces of the upper half portions of the film cutting blades in a bilateral symmetry mode, and air cylinders are arranged above con