<p>Dynamic response and fatigue damage of tension-leg floating wind turbine foundation are studied in this paper. In view of the pain point that the complexity of sea state leads to the low efficiency of traditional time domain fatigue calculation, the sea state combination analysis method is adopted to improve the calculation efficiency of time domain analysis on the premise of ensuring the calculation accuracy. The hydrodynamic response and structural stress analysis in frequency domain are carried out by establishing the dynamic model of tension-leg floating wind turbine foundation, and the fatigue damage statistics of foundation are carried out based on S-N curve and rain-flow counting method. The results show that the foundation should avoid the low frequency resonance range of 0.0 ~ 1.0&#xa0;rad/s, and optimize the hydrodynamic design according to the characteristics of wave incidence angle; the stress distribution of the foundation is less affected by wave incidence angle, showing the mechanical response stability under all-directional load. The fatigue cumulative damage degree is 0.0172 and the fatigue life is about 58 years under high frequency sea conditions. The research verifies the safety of stress level and fatigue life of TLP wind turbine foundation, which provides theoretical basis and technical support for structural reliability design of its engineering application.</p>