The rolls system of eighteen-high mill have been simulated and analyzed by using elastic-plastic FEM with the software MARC. In the model, the elastic deformation of rolls system and the plastic deformation of strip are coupled according to contact condition. Based in simulation, the results of the influence on rolls system bend deformation by roll force and the rolls system bend deformation in the width of strip are gained, and the bend deformation in different directions of work roll is analyzed. All of the analysis can show the theory reference.