Abstract: Taking the 20-high Sendzimir mill as the research object, this paper establishes an integrated finite element model of roll system and rolled stock. Through multivariate simulation, the effects of shape control mechanisms including radial adjustment of backup rolls (As-U-Roll), taper and axial shifting of first intermediate rolls, as well as rolling process parameters on the flatness of grain-oriented silicon steel are investigated. The results show that the adjustment of As-U-Roll for the end back-up bearings can effectively restrain edge drop, while the adjustment of other back-up bearings significantly improves the central flatness. The influence of As-U-Roll adjustment becomes greater closer to the central area of backup rolls. The collaborative adjustment of taper and shifting stroke of first intermediate rolls can effectively mitigate edge thinning of strip steel. In addition, process parameters such as strip width, thickness, tension and rolling speed exert non-linear effects on strip flatness. For grain-oriented silicon steel, cold rolling flatness control and material properties shall be comprehensively considered to inhibit the initiation and propagation of edge cracks and realize stable rolling.