In order to deal with the vibration and stress of key components caused by ship movement when installing wind turbines on double-ship float supports， this paper proposes a rigid-flexible coupling multi-body dynamics analysis method for load transfer during wind turbine installation. A rigid-flexible coupled multi-body dynamic model for the twinbarge float-over wind turbine installation was developed， considering the elastic deformation of key components and its impact on the overall system. Dynamic analysis of the installation and docking process of the wind turbine and foundation was performed， calculating acceleration and stress curves of the wind turbine and key components under various working conditions. The dynamic stress results and vibration characteristics were investigated， revealing that changes in the twin-barge motion period significantly affect the variation pattern of the wind turbine's stress curve. This study provides a theoretical basis for the structural design of the twin-barge float-over wind turbine installation system， contributing to improved stability and safety during the installation process.