In this study, the aero?engine blade is modeled as a cantilever rotating plate with varying cross?section. The blade rotates at a varying speed under the aerodynamic load expressed by the first?order piston theory. At the same time, the pre?setting angle, pre?twist angle and centrifugal force are taken into consideration. The Von Karman plate theory is then applied to derive the nonlinear displacement?strain relationships, and Hamilton′s principle is applied to derive the nonlinear partial differential governing equations of motion.Additionally, the Galerkin method is employed to deduce the partial differential equation into two nonlinear ordinary differential equations. Considering the case of 1 ∶3 internal resonance, the asymptotic perturbation method is used to obtain a four?dimensional nonlinear averaged equation. The numerical method is also used to find the nonlinear dynamic responses of the blade. It is found that the disturbance rotating speed has an important influence on its nonlinear behavior. The frequency spectrum phase, phase portrait, and waveform phase are all presented. It is observed that the blade exhibits the nonlinear dynamics behavior, such as the chaotic, periodic motions and quasi?periodic motions due to the influence of disturbance rotating speeds.