The purpose of the study is to present a model to analyze the spring-back of the thin closed ring after grinding procedure during its manufacture. According to the demands on accuracy and joggling force to the thin ring, a special technology routine was designed. Then, by discussing the routine in mechanics based on rest stress brought by bending, the spring-back moment and the changes of the covered length and the joggling force after grinding were modeled, and a computer aided process planning system named Shuttle was developed and used in simulating the grinding procedure of ring. Finally, the effects caused by thickness of layer cut on such factors as the curvature radius, the covered length and the joggling force during grinding were discussed. The result showed that when the grinding allowance was applied from 0～0.5 mm, the joggling force of samples increased before grinding, but declined after grinding, its covered length was downtrend during that, in addition, the bigger the inertia square of the ring section was, the slower declining of its covered length was, the curvature radius of the sample was climbing up at a different velocity during every process step.