It's necessary to researth permanent magnetic synchronous motor with the advantages such as small volume, low wastage, high efficiency and so on, because energy conservation and environment protection are currently more and more emphasized. Compared with common nonlinear system, however, the permanent magnetic synchronous motor is very sensitive to external load perturbation and parameter change, thus, the stability of permanent magnetic synchronous motor is studied mainly by impulsive control method, the sufficient condition for its asymptotic stability is obtained, and the validity of the results is verified by real examples.