Abstract: The chaotic motion problem of a thin cylindrical shell with two sides simply supported under the coupled action of a mechanical field and an electromagnetic field are studied. The vibration equations of an elastic cylindrical shell under the longitudinal steady magnetic field, together with an annular current and a uniform load are obtained. Then the fourth order Runge-Kutta method is adopted to solve the equations. By changing the electric current, the influences of the electromagnetic parameter on the dynamic system are discussed. The results show that changes of the magnetic intensity as well as the magnitude and the direction of the circumferential current will realize the conversion between the chaotic motion and periodic motion of the thin cylindrical shell with two sides simply supported under the action of mechanical loads.