Rolling mill working roll shape design method and device based on multi-section function fitting

The invention relates to the technical field of metallurgical machinery, automation and rolling, in particular to a rolling mill working roll shape design method and device based on multi-section function fitting. According to the method, the early-stage data statistical analysis stage, the compensation curve determination stage, the cold tandem mill working roll compensation curve expression determination stage and the working roll shape determination stage are sequentially carried out, and the quarter-wave defect of the cold-rolled high-strength steel can be reduced through the design of the working roll shape curve, so that the plate shape quality of products is improved; and inputting the designed roll shape into a grinding machine in a discrete point manner for grinding. The method is high in feasibility and low in cost when being implemented on the cold-rolling mill. After being used on a cold continuous rolling machine in a certain factory, the new roll shape can obviously reduce one fourth of waves of