Abstract: The phenomenon of vortex-induced mutual interference between the tower and blade exists in large-scale wind turbines,significantly affecting their safe operation. This paper investigates this characteristic by using the NREL 5 MW wind turbine as a model.It examines two-dimensional cross-sections where the tower and blade coexist at heights of 65,70,75,and 80 meters from the ground.Numerical simulations are conducted under wind conditions of 6,8,10,12,and 14 m/s,and the results are compared with those from single-tower conditions. The findings reveal severe mutual interference between the blade and tower wakes;compared with the singletower condition,the pressure at a specific point on the tower increases by 1.5 times,and the lift coefficient experiences multiple magnitude responses,with its maximum being about 6 times that of the single tower. Additionally,the wake vortices of the tower and blade appear to merge and share the same frequency,enhancing vortex excitation. The vortex shedding frequency in the combined bladetower condition is lower than in the single-tower case,making it more likely to synchronize with the lower-order natural frequencies of the wind turbine,thereby potentially increasing the risk of resonance.