Spinning forming process is an incremental forming process with no or little cutting and low forming load, which is widely used in the modern manufacturing industry. In this paper, a two-step dividing spinning process for forming a cylinder part with a bottom flange was proposed and studied. The numerical simulations for the spinning process were carried on using finite element method, considering process parameters such as incline angle of the roller, the radius of roller’s fillet, the friction coefficient and the feed ratio. The influences of these parameters on forming load and distribution of wall thickness and strain during the process were obtained and analyzed. The feasibility of the process was confirmed by experiments.