Grid requirements and guidelines for wind turbine does not run off-grid when grid voltage falls within a certain range instantly. To meet this requirement, this paper propose a low voltage ride through control strategy based on battery energy storage. This method decouples PI control strategy through PQ, and appropriately adjusts the amplitude and phase of the AC output side to provide reactive power to meet the system voltage stability, which makes the system has low voltage ride through capability. According to the poor dynamic response characteristics of traditional PI control, this paper uses fuzzy PI control. The results show that compared with traditional PI control, fuzzy PI control has fast response, small tracking error and can enable the system to resume stable operation more quickly after failure.