Inflatable ring type cathode roller breadth control device and control method

The invention discloses an inflatable ring type cathode roller breadth control device and method. The control device comprises a cathode roller, a deflation pipeline, an inflatable ring, a high-pressure air inlet pipeline, an insulating film, an air valve and a pressing plate, and the insulating film annularly wraps the two ends of the outer circle face of the cathode roller; the deflation pipeline is placed between the insulating film and the cathode roller; and the inflatable ring is mounted on the outer side of the insulating film. Through pressure fit between the inflatable ring and the insulating film, copper foil with any breadth can be prepared by adjusting the position of the inflatable ring and the width of the insulating film, and the whole structural size is small, so that the effect of insulating the two ends of the cathode roller in a narrow electrolytic cell range can be achieved. In the preparation process of the copper foil with any breadth, only insulating films with different widths need to