With the development of smart substation project, the feature & role of SCD in the implemented smart substation and the essential requirement of SCD management are illustrated. The paper analyzes the precondition and utility of “offline, online and real time” secondary circuit monitoring of SCD, and the main difference of configurable IED and specified IED in the implemented project based on IEC61850. The characteristic of different SCD monitoring methods based on the different kinds of relays are analyzed, and the assistant approaches are mentioned. Finally, this paper proposes the technical scheme of SCD “design, configuration, operation” integrated monitoring in the future.