Abstract: According to the real condition of different stiffness between the driving side and operating side of some stand mill in a hot strip factory, a calculation module was developed using influence coefficient method based on dual cantilever beam theory to research the regularity of roll elastic deformation under the condition of asymmetrical stiffness. Force analysis of 4-high mill under asymmetric condition was demonstrated, the roll and work piece were discretized following the principle of influence coefficient method, and the key influence functions were presented. The module was used to calculate and analyze the elastic deflection of work roll, the bruise between work roll and backup roll, the bruise between work roll and work piece, the rolling force and roll load distribution in lateral direction between work roll and backup roll with different stiffness differences. The profile of the rolled work piece with different stiffness differences were calculated and analyzed.