By making full use of the digitized and networked features of digital metering system and the extensibility of IEC61850 standard, a remote on-line calibration for digital metering secondary equipment based on the network architecture of smart substation has been proposed in this article. In the concrete implementation, the calibration device is modeled based on application model of electric metering in IEC 61850 project, a special logic node MSCN is used to measure the testing electrical energy, and the calibration data is transmitted to the station control layer through the MMS service, as a result, non intrusive calibration is completed on the basis of the clock synchronization of the metering devices in the station, which has the implementation mode of "On-site calibration " and "background calibration". Moreover, a remote calibration system is designed and developed, and the contrast test results show that the scheme is accurate and feasible.