In order to improve the uniformity of finishing allowance of hypoid pinion cutting by tilted method,an optimization method of roughing summary of the pinion is proposed.In this method,on the basis of known pinion finishing summary,the location of both tooth flanks can be determined according to the pinion tooth size at the middle of gear blank face width.Then,by presetting the initial roughing summary and finishing allowance of the pinion,the finishing allowance of ten control points in both tooth surfaces is achieved.Finally,a genetic algorithm is adopted to conduct an optimization,with the minimum sum of the squares of the difference between the preset finishing allowance and the finishing allowance as the objection function and with the roughing summary of the pinion as the variables.Numerical examples show that,as compared with the Gleason's method,the proposed method decreases the maximum deviations of the finishing allowance on concave and convex by 0.015 and 0.123mm as well as the corresponding root mean squares by 9.52% and 7.98%,respectively.In addition,the measured normal chordal thickness at the toe,middle and heel of a tested pinion decrease respectively by 0.11,0.06 and 0.12mm.The above results demonstrate that the uniformity of the finishing allowance is improved greatly.