<p>Offshore structures are constantly subjected to the complex forces of the marine environment, including wind, sea waves, currents, and seismic loadings. Among these, wind and sea wave forces persist throughout the structure’s lifetime. This study proposes a dynamic analysis approach that incorporates both time and frequency domain methods to investigate the structural responses of offshore structures under the combined effects of wind and wave forces. A wind-wave-pier coupling dynamic model is first developed using a small-scale single pier, with corresponding dynamic equilibrium equations established. Fluctuating wind and sea waves are simulated using the weighted amplitude wave superposition (WAWS) method and linear superposition, respectively. Wind and wave load histories are then derived via Fourier transforms. The structural dynamic responses under different loading scenarios (wind only, wave only, and combined wind and wave) are analyzed using the Newmark-<i>β</i> method. Additionally, the effects of varying wind and wave parameters on structural responses are evaluated. The simulation results demonstrate that the structural responses to wind-wave coupling are smaller than the superimposed effects of wind and wave forces acting independently. When wind speeds are relatively low, wave forces dominate structural displacement and serve as the primary source of vibration.</p>