Abstract: Thanks to the solution of using the two output shafts of the differential mechanisms to drive the two lateral coilers of the slitting line to coil the waste edge,the tensions of both sides of the waste edge can be automatically adjusted during the coiling process. As a result,the waste edge is always coiled under a constant tension condition. Thus the shortcomings of the slitting line,i.e.,the non-tension coiling and broken edge-causing cutting are overcome,and the shearing productivity enhanced.