To enhance the accuracy of gear profile grinding,a compensation method for gear profile deviations by grinding wheel dressing is studied.Firstly,the necessity of studying this method is illustrated,and then the principle of this method is introduced.The tooth profile measurement data is fitted by 3 Bspline curve,the fitting curve equation and the real tooth surface equation are founded.Based on it,in view of the tooth profile deviation compensation,the imaginary tooth surface equation used to calculate the grinding wheel cross-sectional shape is proposed.Based on the different gear measurement data of the same tooth,the different grinding wheel cross-sectional shape can be got,therefore all the grinding wheel cross-sectional shape can form line group,then using least square method to fit the discrete points in line group,the best grinding wheel cross-sectional shape can be got to compensate the tooth profile deviation.Finally,the experiment result shows that the tooth profile deviations could be enhanced to accuracy grade 3 from 5,the tooth profile slope deviation and tooth profile shape deviation are reduced obviously.