Nowadays, wind power has become the focus of development. Under the background of large scale wind farm construction, this paper starts from the importance of wind farm project design and seeks to describe and analyze the current situation and problems of the wind farm design management. In addition, the paper proposes a full life-cycle model of wind farm engineering design, based on which, presents a knowledge management service model as well. On this basis, it designs and develops a management information system for the owner and the other participating units, providing design management, quality management, document management service, and so on. The system provides information management and knowledge management service, so as to enhance the quality of wind farm construction and contribute to the development of wind power industry.