This paper,based on finite element method,analyzed the profile modification of involute spline coupling,and investigated the effects of modified quantity and modified position,as well as considered the effect of profile modification on angular misalignment of involute spline coupling. The results show that: the contact pressure and contact length of modified spline coupling increases with the increase of applied torque. The maximum contact pressure first decreases and then increases when both of modified quantity and modified position increases,and the best modified quantity making the maximum contact pressure minimum increases with the increase of the amount of angular misalignment. The appropriate profile modification of involute spline coupling can effectively reduce the maximum contact pressure and the phenomena of concentrated contact stress,and improve the tooth surface contact pressure distribution,and mitigate the adverse effects caused by angular misalignment.