Abstract: The wake interaction between wind tower and wind turbine blade is very serious resulting in the vortex-induced blade-tower vibration,which substantially affect the safety of the large-scale wind turbine. In this study,NREL 5 MW wind turbine is taken as the research object. CFD and finite element methods are used to calculate its structural characteristics and flow field respectively,and to analyze the modal frequency and mode shape,wake vortex and pressure distribution of blade-tower integration model under different incoming wind speeds. The results show that the fundamental frequency of the blade-tower integration model is small,and the low-order vibration mode mainly shows the oscillation of the whole wind turbine;flap,lag,twist of the blades appear in the high-order vibration mode. The existence of a strong mutually induced wake vortex between the blade and the tower at a height of 65-80 m and 8-12 m/s incoming flow conditions. There is a merging of the vortices between the blade and the tower. The higher the wind speed,the more pronounced the merging phenomenon and the higher the frequency of vortex shedding. The shedding frequency of the wake vortex is close to the natural frequency of the wind turbine when wind speed is in range of 10-12 m/s,which easily leads to vortex-induced resonance between the blade and tower.