By the theory of equivalent substitution,the FT455 model with high precision FT pin-cycloid is used as the carrier,and based on the way of eccentricity modification,the equivalent substitution of stress balanced tooth profile is carried out. To ensure that the tooth profile error is the smallest as target function,the VB programming and MATLAB optimization is carried out,to optimize the design of eccentricity modification tooth profile to replace the stress balanced tooth profile. So that make the meshing tooth number and transmission error of the equivalent substitution tooth profile are within the allowable range,and the transmission accuracy of equivalent stress balanced tooth profile and the stress distribution of the tooth surface are calculated.Through ANSYS finite element analysis of the theoretical programming results to verify the analysis. It is determined that this equivalent stress equalization tooth profile can replace the stress equalization tooth profile.