The invention discloses an automatic ribbon cutting device and method, and belongs to the field of automatic cutting. The automatic ribbon cutting device comprises a base plate, a left movable cutting unit, a full-sheet ribbon, a right movable cutting unit, a movable plate, a guide rail, a pushing air cylinder, a guide block seat, a guide block and a pressing mechanism. The left movable cutting unit and the guide rail are installed on the base plate, the movable plate is installed on the guide rail, the right movable cutting unit is installed on the movable plate, the pushing air cylinder is arranged on the left side face of the movable plate, and the guide block seat is installed on the portion, between the left movable cutting unit and the right movable cutting unit, of the base plate; and the guide block is arranged on the guide block seat, the pressing mechanism is arranged above the guide block, and the full-sheet ribbon is placed between the guide block and the pressing mechanism. By means of the cutting device and method, automatic one-by-one induction counting can be achieved, and when the quality requirement of a notch is met, a single ribbon in the full-sheet ribbon is automatically cut and automatically falls into a stock bin to be temporarily stored for subsequent packaging use.