In order to reduce the effect of aberration on the alignment and enhance the system alignment accuracy in a ATP system,this paper analyzes two position laser displacement （h/s and ra）.It also points out that the two position laser displacement will influence the aberration.This paper has respectively analyzed the effect of a variety of aberrations on alignment precision in the presence of position laser displacement through numerical simulation.The results show that the state of laser emission significantly affects the aberration′s influence on the alignment.Appropriate adjustment to the state of laser will reduce the effect of aberration on alignment and improve the alignment accuracy.