Abstract: Aim at the doublerib wave problem which happened during rolling decoration foil production using a fourhigh mill in certain domestic factory， according to the shape control theory， this kind of strip shape obtained due to the equivalent convexity in the corresponding area of the working roll was excessive. The effects of the factors such as thermal extension and cooling， the roughness and the curve of the working rolls on the equivalent convexity were analyzed. The key factor affected the equivalent convexity of the corresponding area of the working rolls in the worksite. The expression equations of the curve of the working roll was deduced based on references， and the comparisons were made among the curves with different halfangles and different convexity， respectively， therefore， the optimized curve of the working roll under current working conditions was selected. The doublerib wave problem was eliminated after increased the halfangle of the curve of the working roll in the worksite experiment.

Key words: aluminum foil rolling mill, fourhigh mill, doublerib wave, optimization of working roll curve, influence coefficient method