Considering the rigid-flexible coupling system of 5 MW wind turbine, the static pressure, fluid tem-perature, Mach number, vorticity, shear stress and velocity distribution of tower flange are obtained under the combined action of wind shear and fluctuating wind. The dynamic response of rigid-flexible coupling structure is studied by the combined action of the whole vibration and local vibration of 5 MW wind turbine. Through the analysis of dynamic parameter change curve, the improvement measures of tower structure are put forward, and the dynamic response of the structure before and after improvement is compared. The superiority of the improved structure is expounded, so as to provide reference basis for engineering application. (c) 2020 Elsevier Ltd. All rights reserved.