Abstract: An analytical model of section elastoplastic state evolution paths was built for bimetal composite plates under different assemble patterns during bending and leveling based on engineering elastoplastic mechanics. Based on this model, the bending and re-bounding process of stainless steel clad plates was analyzed, the section reverse yield phenomenon during rebounding was explained, and the bending process of stainless steel clad plates was contrasted to that of single material sheets. The results show that five elasto-plastic states of the bimetal composite plate section occurs along with different neutral layer offset laws, and the residual stress distribution is more uneven and may enter the reverse yield state after bending. The relative difference of bending moment between the bimetal composite plate and the single sheet increases with increasing yield strength ratio, and the absolute value first increases then decreases with increasing curvature.