With the minimum amplitude of loaded transmission error of drive gear as the optimization objective

with constructed the modified tooth surfaces

applying the LTCA and used genetic algorithm

on the basis of optimizing the best modification parameter

a large number of common used straight tooth of profile modification are calculated.Then

the data is filtered by using the method of regression analysis and the regression model is built

the optimum amount of modification and the regression formula of the amplitude ratio of transmission error which reflect the modification effect are got.Through the numerical example comparing with existing empirical formula

the correctness is verfied.