Based on the principal stress method, the mathematical model of rolling force for asymmetrical rolling of Cu/Al clad sheet is established.The lengths of different deformation intervals are solved based on the geometric relationship and the deformation characteristics of clad shee. The stress of differential element in different deformation zones is analyzed, combined with the equilibrium differential equation, geometric relationship of deformation zones, boundary conditions and yield criterion, and the rolling pressure in different deformation zones is solved. According to the calculation results, the influence law of process parameters on rolling force, neutral point position and cross-shear zone length is analyzed, which provides a theoretical basis for further research on rolling process.