Abstract: When multiple energy storage units operate in parallel, the traditional load distribution control technology, such as the current-sharing method, is difficult to fully utilize the residual capacity of each energy storage unit. Therefore, how to realize the load distribution among energy storage units according to the difference of residual capacity has become one of the research hotspots of energy storage device control technology. In this paper, the load coefficient of the energy storage unit is defined by using its output current and residual capacity. By combining the load coefficient with the load distribution control circuit which has the structure of double signal buses, a load distribution control strategy based on residual capacity matching is designed to improve the utilization rate of the residual capacity of the energy storage device. In order to enhance the operation flexibility of energy storage units, a flexible thermal switching control method for parallel operation of energy storage units is formed based on the proposed load distribution control strategy. Simulation and experimental results verify the feasibility and effectiveness of the proposed control strategy and method.