Wind energy is widely exploited as a promising renewable energy source worldwide. In this article, an optimization method for the control and operation of the offshore wind farm as an integrated system considering its operational, economic and environmental impacts is proposed. The state of the offshore wind farm development, and the challenges faced by the offshore wind farms, including the challenges of economic costs, operational reliability, and environmental impacts are reviewed and summarized. A systematic methodology is proposed to optimize the costs of an offshore wind farm system based on a framework that extends from the supervisory level dispatch strategies to individual pitch control for load reduction and fatigue mitigation. This holistic approach is able to improve the efficiency and economic performance of a wind farm through overall system optimization, while explicitly operating each wind turbine using a formally designed control framework leading to an extension of their service lifespan. This work provides thorough introduction and innovative solutions for many economic and environmental issues in offshore wind farm development and has strong application potential.