Abstract: To very large DTU 10 MW monopile offshore wind turbine as the research object,by p-y curve and nonlinear spring pile and soil coupling model is set up,select Kaimal spectrum model wind turbulence wind field,and based on P-M wave spectrum defining different frequency distributions,and radiation/diffraction theory is used to calculate the wave load,using finite element method（FEM）of different sea condition order pile type wind turbine dynamic response,fatigue and buckling analysis. The results show that the displacement response and equivalent stress peak of the tower top under different sea conditions and under wave load are far less than that under combined wind and wind wave action,and the displacement response and equivalent stress of the tower top under combined wind and wind wave action are slightly less than that under wind load. The wave load has a certain inhibitory effect on the wind dynamic mechanical response. In addition,compared with the wave load,the wind load is the control load. Under the combined action of wind load and wind wave,the peak value of equivalent stress of wind turbine is located at the connection between tower top and engine room,while the peak value of equivalent stress of wave load wind turbine is located at the connection between support structure and pile foundation. Only using wind load to estimate the fatigue life of wind turbine tower will lead to underestimation. With the increase of wave load,the risk of wind turbine instability increases,and wave load cannot be ignored. Under different sea conditions,the local buckling region under combined wind and wave action is located at the middle and lower end of the tower,which should be paid more attention to when designing wind turbine against wind waves. The variable paddle effect greatly reduces the risk of wind mechanical response fatigue damage and buckling.