Battery equalization management module is one of the most important function modules of battery management system, it can avoid inconsistency by realtime balance management according to the battery status information, which not only improve the battery group capacity utilization rate but also slow down the aging speed of battery group in a certain extent. This paper deeply analyzes the domestic and foreign equalization technology, and compares their advantages and disadvantages as well as applicable occasions according to the equalization circuit, control strategy and system structure of the three aspects , lists the research status of different methods, combined with the battery equalization technology research problems to be solved in series, the direction of its development is prospected.