A three-dimensional（3D） simulation system of wind turbine is constructed based on the virtual reality technology. By using this system， users can learn the structure， the installing process and the inspection process of wind turbines interactively， and roam in the virtual wind farm. Main parts of the wind turbines are modeled， including blades， gear transmission systems， hubs， gearboxes， power generators， towers， etc. A number of animations for demonstrating the structure， the function and the dismounting process of wind turbines are designed and implemented. The installing process and the operating process of wind turbines are also simulated in a 3D manner. A method computing the wind wheel rotating speed through wind speed is proposed. A virtual inspection human model and corresponding action library is built up. The virtual inspection process is controlled based on key points of the inspection paths. Actions can be linked together smoothly by using interpolation technology. An information database for wind turbines is built up， and relative information can be displayed when users inspect the wind turbines or roam in the 3D virtual scenes. The system can help trainees to learn the wind turbines.