Abstract: A structural response prediction method for offshore wind turbines under time-varying corrosion damage is proposed for the time-varying corrosion effect of offshore wind turbines. A time-varying corrosion equivalent model is established that accounts for structural geometric damage and material property degradation, enabling dynamic updating of the structural mechanical performance. Combined with CFD methods, a high-fidelity structural response database covering the entire service life of offshore wind turbines is constructed to investigate the time-varying structural deterioration mechanism. The nonlinear relationship between the structural response distribution and time-varying corrosion damage is clarified. Furthermore, uncalculated data are supplemented using an interpolation and deduction algorithm, realizing rapid and accurate prediction of key structural response data. The results show that the established time-varying corrosion equivalent model can effectively reflect structural performance degradation and realize rapid corrosion modeling of offshore wind turbine structures. The structural response database constructed with CFD technology can reveal the evolutionary characteristics of structural responses. Error analysis of the sampling strategies indicates that the errors of stress and deformation under the dense sampling strategy are 0.31% and 2.23%, respectively, and the moderate sampling strategy still maintains satisfactory accuracy. Although the errors of the sparse sampling strategy increase to 3.31% and 8.71%, the overall evolutionary trend of the structural response can still be accurately captured.The prediction method proposed in this paper can quickly and effectively reflect the nonlinear relationship between structural response characteristics and corrosion damage evolution of offshore wind turbines, and can provide technical support for the design optimization, long-term performance evaluation and operation and maintenance decision-making of offshore wind turbine structures.