A combined model system (WRF/WT) of the mesoscale model WRF and the Meteodyn WT, a CFD model from France, was carried out the numerical simulation experiments of regional wind resources over Hailing Island of Guangdong Province with a horizontal resolution of 100 m × 100 m. The observational data from 7 wind towers in Hailing Island were used to test the results modeled by WRF/WT, and compared with the simulated errors to the single point wind parameters, thus studying the feasibility of WRF/WT model system in micro siting for wind farm and the application of distributed development of wind power and utilization. The results showed that, the combined model system of mesoscale model and CFD model in simulating the trends of the regional wind energy resource distribution is more accurate than CFD model used only; the WRF/WT model system used in complex terrain for wind resource numerical simulated evaluation is feasible, and its accuracy in simulating the parameters of the regional wind energy resource distribution is close to the result of WRF/WAsP simulating within 2 km. The WRF/WT model system compared to WRF/WAsP has obvious advantages when the frequency distribution does not meet the Weibull distribution or in a steep terrain. In the future, we need to further research in the interface methods of mesoscale model and CFD models, and the error correction of mesoscale model simulations.