Effective combination of simplified plate theory (SPT) and the improved Fourier-Ritz method, a unified analytical model for the vibro-acoustic property of a laminated rotary plate coupling with an impedance cavity under complex boundary conditions is established in the investigation. The structure-acoustic coupling potential energy generated by the interaction between the flexible laminated plate and the cavity at the interface is added into the energy functional of the structure domain and the acoustic domain, and the energy functional of the plate-cavity coupling system is obtained. The solution equation of the vibro-acoustic coupling property can be gained through Rayleigh-Ritz energy technique. Besides, by introducing external force or internal sound source, the coupling mechanism between the flexible plate and the cavity is explained thoroughly from two aspects. By comparing the results calculated by the classical plate theory (CPT), the finite element method (FEM), the first-order shear deformation theory (FSDT) and Experimental test, the applicability and accuracy of SPT in analyzing the rotary laminated plate-cavity coupling system are verified. Besides, the effects of geometric parameters, material parameters, elastic boundary conditions, acoustic medium on the coupling system are mainly studied, which provides theoretical guidance for the design and noise control of such engineering structures.