Abstract: Aiming at the problem of decreased simulation accuracy caused by communication interface delay and multi-rate sampling in multi-disciplinary co-simulation of offshore wind turbines, an optimized interface data exchange technology was studied to improve the simulation accuracy of gas-mechanical-electro coupling characteristics. An interface-optimization scheme based on Hermite interpolation was proposed, a mathematical error model was established to compare the error magnitudes of the zero-order hold (ZOH) with the optimized interface. A simplified electro-mechanical co-simulation platform was constructed to verify the interface performance, and the optimized interface was then deployed in a fully coupled offshore-wind simulation system. Results show that in the simplified second-order test, the Hermite-interpolation interface reduces the simulation error magnitude significantly. In the full electro-mechanic simulation, after adopting the optimized interface data exchange scheme, the fidelity of the system is significantly improved, and the response characteristics are closer to real working conditions. By refining the data transfer among cross-disciplinary models, Hermite extrapolation effectively eliminates interface-induced distortions in co-simulation.