Objective To address the practical challenges of spatial saturation and escalating sea-use conflicts in nearshore premium renewable resource zones, and to overcome the limitations of single-energy development models, there is an urgent need to validate the dynamic performance and safety of multi-energy complementary floating platforms under complex sea states.

Method In response to the need for validating the dynamic performance of multi-energy complementary floating systems in complex sea conditions, this study took a 2 MW hybrid system as the research object. A physical model with a 1:50 geometric scale was constructed. A comparative study between model tests under irregular waves and a fully coupled time-domain numerical model was conducted. The time-frequency domain characteristics of the surge displacement under normal, extreme and survival conditions were analyzed and compared.

Result The amplitude of the floating body's motion response increases significantly with wave height and period. The mean surge displacement is greatest at a wave direction of 0°, while non-zero incidence angles lead to reduced responses due to energy dispersion. The numerical model's prediction accuracy meet engineering requirements in the time domain and low-frequency range. However, deviations are observed in the high-frequency range, attribute to the truncation of higher-order wave harmonics, incomplete modeling of damping effects, and limitations in simulating physical basin boundary conditions.

Conclusion This research validates the effectiveness of the experimental-numerical synergistic method, while also indentifies the areas for improvement in predicting high-frequency nonlinear responses. It provides a scientific basis for the design and safety assessment of deep-sea multi-energy complementary systems.