Abstract: In order to analyze the effect of microstructure under different thermo-mechanical control processes（TMCP） on the fatigue performance of S460 offshore wind power steel,this work selected the S460-14 sample with the best comprehensive mechanical properties and the comparison sample S460-11 based on the previous experimental research results for fatigue performance testing. Through the mechanical properties,fracture morphology,EBSD observation,and texture analysis of S460 steel,the fatigue behavior mechanism of S460 steel for offshore wind power was revealed.