Abstract: Lithium-ion battery packs are generally composed of multiple single cells connected in series and parallel to meet the needs of different voltage levels and capacity applications. Due to the inconsistency of the single battery itself or the difference in the external environment, the single battery will be overcharged or overdischarged during the use of the battery pack, which limits the overall performance of the battery pack to a certain extent. Aiming at the problem that the traditional balancing strategy needs to accurately measure the voltage of the lithium battery, a lithium battery pack balancing circuit and strategy based on voltage balance is proposed. The balancing strategy uses a voltage difference amplifier circuit to amplify the voltage difference between adjacent single cells or adjacent battery packs, and uses the voltage difference signal and the reference voltage to determine the cell balance direction to achieve the cell balance of the series battery pack. The solution does not need to accurately measure the voltage of the lithium battery, the system structure is simple, and the modular design is easy, avoiding the use of high-precision voltage sampling chips, and reducing the equalization cost. The topological structure, working principle and control strategy of voltage difference amplifier circuit and equalizing circuit are described in detail, a Matlab/Simulink simulation model is built to verify the feasibility of the proposed equilibrium strategy.