The invention provides a rolling method and device applied in a transition section of a cold tandem mill. According to the rolling method and device, first strip steel and second strip steel are obtained, wherein the first strip steel and the second strip steel are adjacent strip steel; weld joint positions of the first strip steel and the second strip steel in real time are obtained; and a rolling mode between position control and constant rolling force control is switched according to the welding seam positions of the first strip steel and the second strip steel. The technical problems thatin the prior art, when the cold tandem mill is rolled in a variable specification and has welding seam defects or raw material defects existing near weld joints, belt breakage occurs easily, and the productivity is seriously affected are solved. The rolling method and device have the advantages that the rolling process of cold tandem mill sets is digested from the rolling technology through the switching of the rolling modes, so that a strip breakage problem easily caused by a original rolling mode is avoided when the strip steel changes specification transition, the weld joints have defects or the raw material defects exist near the weld joints; and the problem that a rack needs to be opened due to defects in the weld joints or near the weld joints is avoided, so that the time is saved, and the technical effect of the productivity is improved.