To address the limitations of existing state of health (SOH) balancing strategies for series-connected lithium-ion cells, such as the need for a centralized controller, extensive global communication, and high system costs, this paper proposes an active SOH balancing strategy based on a consensus algorithm. The intrinsic relationship among SOH parameters, depth of discharge (DOD), and active power is analyzed, and an active power allocation and control algorithm switching rules are designed. A consensus algorithm is used to solve the average value of DOD, achieving SOH balancing without requiring a centralized controller and reducing communication signal requirements. This approach enhances battery capacity utilization efficiency and lowers maintenance costs. Finally, Matlab/Simulink simulations demonstrate that the proposed scheme can achieve self-balancing of SOH within a series-connected lithium-ion battery pack, even with load variations, communication interruptions, increasing number of battery cells, and DOD measurement errors.