Sheet metal thickness of single point incremental forming deforming deformation zone is one of the important factors affecting parts strength and quality,it is believed that thickness follows the law of cosines and only depends on the size of the forming angle. This paper mainly research on deformation zone of conical parts from theoretical calculation and finite element simulation and experiment of these three kinds of aspects. It is research deformation thickness that is divided into several quarters,and analyzes the impact of tool head diameter,spacing of layers,the pressure plate’s inner diameter and the trajectory of forming on thickness of each region. The results show that a large tool diameter and small inner diameter of the plate can help to reduce to the thickness thinning rate,and improve the degree of uniformity of thickness; the large layer spacing can be increasing to thickness reach a stable value of speed; pressing point uniformly distributed trajectory can increase the minimum thickness and the average thickness,and has no effect on the degree of uniformity of thickness.