The embodiment of the invention discloses a method, a management equipment and a system for automatically expanding capacity, relating to the technical field of communication and solving the technical problems of low searching efficiency caused by a discontinuous ID segment managed on management nodes in the prior art. When new joints in the embodiment of the invention are added, the new nodes receive added management node information from a node management server, the added management node information at least includes address information of added management nodes; continuous indexes of an ID segment are obtained by utilizing the address information of the added management nodes; added information of the new nodes is sent to all the added management nodes, and the added information at least comprises a continuous ID segment managed by the new nodes and address information of the new nodes. The embodiment of the invention is mainly used for management of data storage.