Abstract: Based on mechanical and electrical analytical dynamics,we established equations about vibration coupled with mechanics andelectrics in AC motor set. Using the theory of differential dynamic system,destabilizing oscillation of the AC motor's were analyzed with electricityand mechanics coupling. By Center Manifold, theory of stability with multipleparameters and unification technique to analyze the high-codimbifurcation occurring in the system, the Normal Form of the originalsystem is obtained. The bifurcation situation and the stabilization of thebifurcation solution are discussed in detail. In addition, a detailednumerical analysis is made, its results are in agreement with the theoreticresults. Also, we got the further result in vibration when AC motor lose itsstability.