This paper proposed a remote on-line calibration method for gateway energy meters. The implementation is adding sets of high precision voltage and current pre-acquisition devices at the position of measurement points, to get more accurate voltage, current, electric energy pulses, field temperature and humidity information of the gateway measurement points. Then the devices upload this data to the gateway meters’ online maintenance management system after compression. The master station will work out their electric energy and compare with the value measured by the observed meters, to estimate the relative error of them. In addition, health assessments of the meters are given according to the preset electric energy meter fault models. Moreover, warning information of the gateway energy meters that may have problems are prompted to determine the best timing to schedule verification. Thus, an operation management mechanism that start check since error is found is established.