Abstract: Based on Ansys finite element software, a three-dimensional solid modeling of the tower system of the NREL 5 MW monopile offshore wind turbine was conducted, and the influence of the blade rotation state and soil-structure interaction on the vibration characteristics of the tower was analyzed. Results show that considering the centrifugal force and centrifugal stiffness generated by the blade rotation, the soil-structure interaction can significantly reduce the first two modal frequencies of the tower, and the relative variation of the first two modal frequencies are-31.68% and-31.74%, respectively. At the same time, the transient displacement response value of the tower increases, and the maximum displacement of the tower top in fore-and-aft and lateral directions can be increased by 86.94% and 46.59% respectively compared with the fixed constraint at the bottom. Under the combined action of blade rotation and soil-structure interaction, the equivalent stress of the tower increases significantly, and the maximum equivalent stress can be increased by 57.38%; the first and second order modal frequencies will resonate with the blade 1 P rotation frequency when the speed reaches around 9.5 r/min, and will not resonate with the blade 3 P rotation frequency within the rated speed.