To advance global sustainability and meet climate targets, the development of reliable renewable energy infrastructure is paramount. Offshore wind energy is a key factor in achieving this goal, and ensuring its operational efficiency requires a deep understanding of the sources of uncertainty faced by offshore wind turbines (OWTs). This study proposes and implements an integrated framework for sensitivity analysis (SA) to investigate the key sources of uncertainty influencing the dynamic response of an OWT. This framework is based on the XGBoost surrogate model and Sobol’s method, aiming to efficiently and accurately quantify the impact of various uncertain parameters. A key methodological novelty lies in the integrated use of Sobol’s method and SHapley Additive exPlanations (SHAP), which provides a unique cross-validating mechanism for the sensitivity results. This study demonstrates the strongly condition-dependent nature of the OWT’s sensitivity characteristics by analyzing design load cases. The results indicate that wind speed is the dominant factor influencing the structural response under normal operating conditions. In contrast, under extreme shutdown conditions, the response of the OWT is primarily governed by the physical and material properties of the structure. In addition, the high consistency between the results of SHAP technology and the SA results obtained by Sobol’s method confirms the reliability of the proposed framework. The identified key sources of uncertainty provide direct practical insights for design optimization and reliability assessment of OWTs.

Wind–wave misalignment is a pervasive environmental phenomenon that significantly affects the structural integrity of floating offshore wind turbines (FOWTs). For a Spar-type FOWT across the full 0°–90° misalignment range, this study systematically conducts dynamic response characterization and parameter sensitivity analysis, quantifying the directional modulation effects on five critical dynamic indicators, including tower-base Fore-Aft (F-A) and side-to-side (S-S) bending moments, maximum Von Mises stress, and fairlead tensions. Results demonstrate that wind–wave misalignment triggers a significant redistribution of structural energy, where side-to-side bending moments and fairlead tensions exhibit distinct peak characteristics at specific non-collinear headings. Rather than merely evaluating structural responses, this study emphasizes the sensitivity of environmental parameters to reveal a dominance-switching mechanism. As the misalignment angle increases, the governing factors of structural response dynamically shift from wind variables to wave variables. This research provides a rigorous mechanical explanation for complex response evolution and offers a scientific basis for the robust design of floating wind turbines in multi-directional sea states.