Because of the complex roll system of the 20-High Sendzimir mill, the calculation of the driving torque is different from the 4-High or 6-High rolling mill, except the rolling torque M_R, the friction torque M_f cannot be ignored, and the friction torque M_f is consist of the friction torque caused by the rolling friction between the rolls M_f^R and the friction torque to overcome the friction in the backing bearings M_f^B. On the basis of the force analysis of the roll system, the driving torque of the 20-high Sendzimir mill was calculated and analyzed, include the torque M_R, M_f, M_f^R and M_f^B, the composition and distribution law have been gained; what’s more, the contact stress between rolls was also calculated, these are significant for the design of the 20-High Sendzimir mill.