The theoretical modeling is the critical step to ensure the safe, sustainable and stable operation of the engineering structure in the design phase, especially in the dynamical characteristics analysis. The reduced order procedure of the composite structure’s dynamical model is required so as to nonlinear dynamic analysis and controller design. However, the traditional dynamical model that established by the modal function of a single component is based on the classical statically indeterminate boundary conditions. There exists the significantly difference compared with the modes obtained by the whole structure. The global mode theory can reveal the coupling effect between rigid motion and flexible deformation of the structure, and provides the global mode that can accurately reflect the vibration of the combined structure. In this paper, the research progress of the global modal method in the reduced order for the combined structure dynamic model such as cables, beams and plates in recent years is given. The solving method for the global mode method of the multi-rigid-flexible coupling system based on the Cartesian and Lagrange coordinate is mainly focused. The application of the global modal method in the analysis of natural characteristics of the complex combined structure is illustrated by the examples such as the multi-beam rigid connection, cable-beam combination and rigid-flexible coupling spacecraft. Multiple research results show that the global mode method not only overcomes the dependence on the mode form and quantity of the traditional method, but also shows the prominent advantage in revealing complex dynamic phenomena, optimizing structural design and vibration control.