With the continuous improvement of production technology and higher requirement for product quality, users are increasingly strict about the quality of surface and plate shape of rolled copper foil. In view of the serious plate shape problems of rolled copper foil by X-type rolling mill, taking the rolling process of copper foil with width of 630 mm and thickness of 18 μm as an example, the influences of the rolling passes, the tension control and the backup roll profile on the plate shape problems of the doublerib wave, the middle and double waves are analyzed emphatically, and the corresponding solution is put forward in the paper. The results showed that: ① under the condition of the same total processing rate, the plate shape problems can be effectively improved by reducing rolling passes, which can generate more deformation heat per rolling pass to release residual stress; ② the plate shape can be effectively regulated by appropriately increasing the tension, and adjusting the inlet tension and export tension equal; ③ setting the backup roll crown as 0.3 mm, and grinding secondary roller profile of backup roll can also be beneficial to plate shape.