The present invention relates to an isolating two-way constant-current maintenance system based on a power supply of shared equipment, comprising a power supply, an electronic switch K1, a current sensor, a main battery management system controller, and a plurality of secondary battery management system controllers; wherein the power supply is connected with the current sensor; the current sensor is respectively connected with the electronic switch K1 and the main battery management system controller; the electronic switch is respectively connected with the main battery management system controller and the secondary battery management system controllers; the main battery management system controller is respectively in a communication connection with the plurality of secondary battery management system controllers; and each one of the secondary battery management system controllers is connected with a battery pack. The isolating two-way constant-current maintenance system based on a power supply of shared equipment has the advantages of small size, low cost, high power conversion efficiency, two-way and constant maintenance, and low requirements on the power supply. The system can quickly enhance the utilization rate of the battery and effectively prolong the service life of the battery pack.