The updating geometric method was proposed to simulate the deformation behavior of workpiece during multipass shape rolling by using finite element method. Firstly, establish and solve the finite element model of the first pass shape rolling process, then update the geometric shape of workpiece after the first pass and delete rolls of the first pass, establish and mesh rolls of the second pass, modify the boundaries and material parameters of workpiece, and solve its deformation behavior during the second pass shape rolling. With the same steps, its deformation behavior during the following passes rolling could be solved. The method was applied to simulate the deformation behavior of a cube workpiece during six-pass H-beam rolling with split-rolling, and its shapes after every pass rolling process were obtained. Experiments on the deformation behavior of slab during multipass rolling were carried out by using pure lead in an experimental mill. The calculated results are in good agreement with the experimental ones.