ABSTRACT：   With the fast development of social economy, the composition of power load becomes more complicated, and the integration of new energy in the distribution network also makes the problem of load peak and valley worse. Battery energy storage system, with its characteristics of rapid response, precise control and energy bidirectional flow, becomes an effective program to achieve ‘cutting peak filling’ in power system. This paper proposes a variable power control strategy for battery energy storage involved in peak load shifting in distribution networks. This strategy takes one day as the time scale and the energy balance of the energy storage system as the criterion, which effectively improves the peak-problem of distribution network. Taking the actual load data of a power substation as an example, the effectiveness of the proposed method is verified by comparing the proposed variable power strategy with the commonly used constant power strategy based on the proposed evaluation index.