：The continuously elastic-plastic mechanical behavior of the plastic hardening material is analyzed by the elastic-plastic bending theory and stress linear superposition principle,and a continuous elastic-plastic bending-straightening processing mechanical model of the leveler with seven rollers is established considering the effect of stress transfer effect on straightening process. By comparing the experimental results and theoretical calculations,the average deviation is less than 8%,which verify the theoretical analysis is correct. Using this model,different straightening strategies are analyzed. The results show that the large deformation straightening strategy is better than the small deformation straightening strategy in the controlling ability of the residual stress and residual curvature. Because of stress transfer effect on straightening process,the residual curvature does not converge to zero but fluctuate within a certain range with the straightening processing by the small deformation straightening strategy; The large deformation straightening strategy adopts gradual straightening process setting method,so it can achieve the purpose of straightening. All these results provide a theoretical basis for straightening strategy selection in industrial production.