The invention provides a heat shrinking technology for improving a membrane wavy edge. The heat shrinking technology includes the following steps that rewinding rollers are prepared, a plurality of shrinkable buffer strips are arranged on the outer surfaces of the rewinding rollers at equal intervals, and all the buffer strips and the rewinding rollers are parallel in the axial direction; 2, membranes are wound around to the rewinding rollers provided with the buffer strips; 3, the rewinding rollers wound with the membranes are baked at the certain temperature, and baking is kept for certain time; 4, the baked membranes are taken out and cooled at the normal temperature; 5,the surfaces of the cooled membranes are coated with slurry with the certain thickness. The heat shrinking technology and device have the advantages that the membranes are even accordingly, the poor waves are reduced after the membranes are coated, the over-specification radian and the over-specification size after the membranes are cut to small strips are decreased, the superior product rate of the membranes is increased, production resources are reasonably used, and waste is reduced.