Abstract: Fatigue is one of the major factors controlling the safety of foundation for offshore wind turbines. The fatigue research of the new all-steel bucket foundation for offshore wind turbines is carried out in this paper based on the random wave theory and spectrum analysis method,the fatigue damage accumulation calculation method that the structure alternating stress under long-term sea state obeys Rayleigh distribution is discussed. The cumulative fatigue damage and life of the all-steel bucket foundation for offshore wind turbines is calculated based on the aforementioned theory,the results indicate that the main fatigue failure points of bucket foundation centrally located in the intersection of the diagonal brace and the cylinder. According to the previous results,local geometry of the structure is optimized. Comparison of results indicates that the geometric optimization of key parts can greatly reduce the degree of stress concentration and cumulative fatigue damage. Meanwhile,it verifies that the fatigue calculation results have high sensitivity to the level of hot spot stress.