Evaluation method for cold-rolled sheet shape of twenty-high roll mill

The invention relates to a twenty-high roll mill cold-rolled plate shape evaluation method, which is characterized in that real-time online automatic evaluation of a plate shape is formed based on evaluation indexes cooperatively set by a plate shape instrument; the evaluation indexes are established for each section in the plate width direction and comprise an edge wave evaluation index, a 1/4 wave evaluation index, a middle wave evaluation index, an edge wave symmetry evaluation index and a 1/4 wave symmetry evaluation index; wherein the edge wave evaluation indexes aim at a working side edge wave area and a transmission side edge wave area, and the corresponding edge wave area is determined according to the taper of the roller body; wherein the 1/4 wave evaluation indexes aim at a working side 1/4 wave area and a transmission side 1/4 wave area, and the corresponding 1/4 wave area is determined based on historical actual detection data. According to the method for evaluating the cold-rolled plate shape of