The invention discloses a direct-current micro-grid system. The direct-current micro-grid system comprises a plurality of distributed power supplies and a smart manager, wherein output ends of the distributed power supplies are connected to a direct-current bus through DC/DC converters and a distributed power supply side direct-current breaker in sequence; the direct-current bus is connected with a bilateral AC/DC current transformer through a power grid grid-connection side direct-current breaker; the bilateral AC/DC current transformer is connected to a large power grid through a transformer and a grid-connection point switch in sequence; the direct-current bus is connected with a smart home load through a load side direct-current breaker and a load DC/DC converter in sequence in order to supply electric energy to the smart home load; the smart manager is connected with the bilateral AC/DC current transformer, the distributed power supplies, the DC/DC converters connected with the distributed power supplies, and the distributed power supply side direct-current breaker respectively; and the smart manager comprises an energy management system and a running controller.