The lateral bend forming is a new flexible forming method which bend section steel into parts with all kinds of curvature. The main principle and advantages of lateral bend forming is introduced. Mathematical model of lateral bend forming is established based on finite element method. Contact problem is treated. The law of forming force versus process parameters is analyzed by numerical simulation technology. The results shown as follows: the forming force is increased with the increment of the pressing quantity; the higher yield limit of material is, the bigger forming force is; the forming force of angle steel is bigger than sheet metal without changing other parameters.