This article puts forward the similarity between the instantaneous acceleration center of plane motion of rigid body and the acceleration center of the fixed axis rotation of rigid body and gives the method of locating the instantaneous acceleration center of plane motion according to the characteristic of the rotating center of the fixed axis of the rigid body. Four special cases are also shown in this article. Practical examples are used to illustrate the application of the instantaneous acceleration center in dynamics. The solutions to certain problems are greatly simplified by combining the instantaneous acceleration center with the theorem of moment of momentum of relative motion.