Using electroplating CBN hard gear-honing-tools with standard involute, the vicinity of the workpiece tooth pitch circle will be a “mid concave” error, the root of the tooth will be a “dig root” error generally. For the formation factors of the error are more complex, it is difficult to calculate errors with an exact analytical method. To this end, by using Pro/E and ANSYS software, the contact analysis of electroplating CBN hard honing process was simulated. The honed tooth surface normal deformation analysis was the important means to determine extent of tooth profile error, through the normal deformation analysis based on simulation results, the location and extent of normal deformation was determined. Practice shows that the location and extent of the normal deformation has been a certain relationship with processing gear tooth profile errors. It is provided a theoretical basis to make the gear-honing tooth surface modification as possible.