Abstract: In order to smooth the output of wind farms, energy storage devices with certain capacity are often configured in wind farms. However, due to capacity limit, the service life of energy storage system can be affected by excessive charge and deep discharge. In this paper, two performance indicators that characterize battery energy storage system operating conditions are presented, and the fuzzy adaptive control is introduced to optimally control the wind farm energy storage system. The proposed fuzzy adaptive control strategy is used to adjust power reference value of energy storage system. It does not only restrain wind power fluctuations and improve the stability of wind power output, but also avoids the occurrence of over charge and deep discharge of energy storage system, which effectively prolong the service life of the energy storage system. In the end, simulations of cases with or without the fuzzy adaptive control system have been made,and the correctness and effectiveness of the proposed control strategy are verified by the simulation results.