Magnetorheological finishing(MRF) can be used for final surface modification and subsurface residual damage modification of various geometrical features such as planes and curved surfaces. However,in engineering practice,curvature like components are often difficult to obtain equivalent convergence accuracy and convergence efficiency as planar components of the same level. Theoretically,the uncertainty of MRF introduced by the curvature factor of the curvature element cannot be quantitatively analyzed and evaluated. In this paper,based on the characteristics of MRF process,the dependence of curvature characteristics and polishing process is discussed. And further,the influence mechanism of curvature characteristics on various process links is established based on geometric analysis. It includes the influence mechanism of curvature on surface error development,trajectory planning,removal function acquisition,dwell time solution and machine tool error tolerance. Finally,the evaluation theory of curvature effect of MRF finishing facing curvature element is established.