In the production of variable wall thickness cylinder parts，there are many questions of low material utilization process, long machining man-hour, high production costs. In order to solve these problems, a new method of rolling-extrusion process was put forward. In this process material is formed by means of three passive rotational tools. The charge is provided by means of a pusher pushing the billet in a working space between the profiled rolls. In this paper, the authors focused on determining the forward slip of rolling-extrusion process to get the precision size control of this part.Deform-3D were used to verify the forward slip model and feasibility of the processes. The production test showed that the parts can be produced accurately using rolling-extrusion technique and the material utilization was increased by 19%.