A transverse cutting system for a machine for the production of plastic film includes a supporting structure carrying a cutting unit, which are moved between a rest position away from a path of a plastic film being wound and an operating position along the path of the plastic film; a rotating support carrying a hot wire; a rotating cap, associated to an idle roller and arranged transversally to the path of the plastic film that is moving forwards, and an actuator, which controls the rotation of the rotating support carrying the rotating cap and causes the rotating cap to interfere with the plastic film before the hot wire also interferes with said plastic film. The same plastic film, owing to the friction force generated by the rotating cap, entrains it with it, causing the rotating cap to equalize the linear velocity of the plastic film.