For the special structure of cylindrical inner surface of a Wolter-I grazing mirror, the removal function of an elastic ball tool with deflected rotation motion was researched,and the relations between the max removal depth of removal function, dwell time and other parameters obtained by experiments were demonstrated.By using a 2-step method for polishing, it shows that when the ratio of rotating angle velocity to tool-workpiece is 1.41, the surface quality is in the best state. Furthermore, the fabrication of Wolter-I grazing mirror base on Computer Control Optical Surface(CCOS) was introduced. In the research, Zerodur glass was selected as mirror substrates and it was polished by CeO abrasive on a Digital Control(NC) platform developed by ourselves. By changing the distance between the tool and the workpiece, the removal functions in different contact areas were determined in the experiments, and the residual error from previous polishing process was corrected effectively. Using two kinds of measurement devices to outline the surface profile, it shows that the final surface figure of the mirror is 1.39 μm (PV), 0.34 μm (RMS) and the error of circularity is less than 0.1 μm (RMS). These results demonstrate the feasibility of fabricating Wolter-I grazing mirror with the 2-step deflected rotation method.