The first four vibration modes of complicated multi-body system for the Z-type folding wing through different methods are obtained. Firstly, the Z-type folding wing is divided into three components: the inner wing, the middle wing and the outer wing, and these wings are then treated as carbon fiber composite laminated plates which are connected to each other through two rigid hinges. The transform of three Cartesian coordinate systems are used to connect these three plates. The inner side of Z-type folding wing is fixed with fuselage. The middle wing is treated as simply supported on its four edges to connect with the inner wing and the outer wing. The outer side of Z-type folding wing is free end. Meanwhile, the supposed driving force of moment (I) is applied in the first hinge to provide the angular velocity. In addition, the first plate and the third plate are supposed to be always sustained parallel, which is carried out under the supposed driving force of moment (II) applied in the second hinge. And there are harmonic forces on the second plate and the third plate. Secondly, dynamic equations of nonlinear vibration of the Z-type folding wing are deduced using the Hamilton principle and von Karman large deformation theory. Furthermore, through the ANSYS analysis of modes and harmonic response based on the real material parameters and theoretical data on the boundary conditions of these plates, we establish appropriate mode function. Subsequently, the calculated mode function is confirmed by the numerical simulation. Finally, we can conclude that the mode shape of Z-type folding plates is similar with the mode shape of cantilever plate. The results not only offer theory foundation for discrete analysis of dynamical equations through Garlarkin approach, but also provide theoretical reference for the future design and experiment of the folding wings.