The present invention discloses a primary equipment maintaining method for a power SCADA system, comprising following steps: (1) acquiring information about a corresponding primary device in a space; (2) calculating all connected devices from the information of the primary device; (3) acquiring a boundary defining mode of the primary device from a configuration file; (4) determining a search range according to the boundary defining mode and a topological connection relation; (5) during the search, storing related information of the primary equipment; and (6) storing the correspondence between the space and the primary equipment in a database. The method in the present invention describes a central element and boundary elements by means of the space, and assigns the primary equipment contained in the space by means of the correlation between the space and the primary equipment, so that it is convenient for workers to maintain the equipment with the advantages of high automation degree, precise calculation and simple maintenance.