The nonlinear dynamic behavior of the micro actuators is analyzed in this paper. In general, analysis of the electrostatic device is quite difficult and complicated due to the electrostatic coupling effect and the nonlinear electrostatic force. In this study, a hybrid method for the micro-structure system, which combines the differential transformation and finite difference approximation techniques, is used to overcome the nonlinear electrostatic coupling phenomenon. The analysis takes account of the electrostatic coupling effect, the fringing field effect, the residual stress, the nonlinear electrostatic force and squeeze-film damping effect. Finally, the actuating conditions which ensure the stability of the micro actuators are identified by reference to phase portraits.