Objective: With the increase of wind turbine single capacity installation, the safety performance problems brought by the lightweight design of transmission system aiming at improving power density have been widely concerned. In view of the highly integrated design of wind power transmission system, not only the influence of variable excitation caused by external random wind load, but also the mechanical and electromagnetic internal excitation factors should be considered. Therefore, it is particularly important to study the electromechanical rigid-flexible interaction of wind power transmission system. In this paper, the electromechanical rigid-flexible coupling characteristics of the integrated system are explored by constructing an integrated system model. Methods: In this paper, aiming at the integrated structure of wind turbine transmission system, an electromechanical rigid-flexible coupling dynamics model is proposed which can using for variable-load and variable-speed condition. This model not only takes into account the mechanical factors such as time-varying meshing stiffness of gears, phase relationship, structural flexibility of shaft and shell, but also considered electromagnetic factors as saturation characteristics of permanent magnet, radial force wave and space harmonic wave. Runge-Kutta method was used to solve the dynamic model. The electromechanical coupling dynamic characteristics of the gearbox-generator integrated system are studied, the influence of housing flexibility on the dynamic characteristics of the system is discussed, and the speed-up analysis method is proposed to discuss the resonance speed of the system. Finally combined with modal energy method and vector distribution principle, the potential dangerous components in resonance are found. Results: The results show that the meshing frequency (fm) and the electromagnetic excitation frequency (fe) in the dynamic meshing force of the gear system. The generator vibration signal, output current and electromagnetic torque all contain the gear system meshing frequency (fm), electromagnetic excitation frequency (fe) and their modulation frequency (nfm+mfe). The increase of housing wall thickness enhances the electromechanical coupling effect of the system. The change of housing thickness has little effect on the torsional characteristics of the gear generator. It mainly affects the translational vibration characteristics of each component of the gear system. When the system using thin - walled housing, a new resonant speed caused by the electromagnetic excitation of the generator appears. When the housing wall thickness increases, the modal strain energy of the system changes, which effectively improves the damage caused by the planet-ring meshing strain energy of the inner gear ring and the planetary gear. Conclusion: The gear system and generator system have strong coupling characteristics, and the change of housing thickness strengthens the electromechanical interaction. The gear frequency component and the modulation frequency component in the current signal can be used to detect the operating characteristics and fault diagnosis of the gear system. For the integrated system, the influence of generator electromagnetic excitation and gear system excitation characteristics on system resonance should be considered in the design of housing thickness. Selecting reasonable housing thickness can effectively improve the safety and reliability of the system, reduce the resonance area and reduce the damage of system components.