Sheet incremental forming (ISF) is known for short lead time and requiring no dedicated dies.Thickness thinning, however, has always been a puzzle which hinds the wide application of ISF.And little work has been done on the mechanical property of the material after ISF process.In this work, based on a truncated pyramid, a finite element method (FEM) model was set up and then experimentally verified.The tool path of the simulation model was assured to be the same with that of the real process by adding the displacement constraints on the forming tool.Afterwards, the sine law which was often used to predict the ultimate thickness was verified, but it only applies to the region mainly subjected to pure stretching deformation.Additionally, the relation between tool path and the minimum thickness and its location has been discussed.The result indicates that the minimum thickness is much related to tool diameter if traditional tool trajectory is employed, and its location is largely decided by step depth.Finally, tensile tests with specimens from the formed pyramid were carried out.It indicates that the plasticity of the material decreases sharply but the strength increases markedly owing to the significant work hardening effect during ISF process.