In the digital power metering system, the accuracy of the digital electric energy meter must be calibrated as it is related to the reliability and fairness of energy measurement. National standard and State Grid’s enterprise standard for digital meter are issued not long ago. At present, there is no complete calibration program for digital meter. In this paper, an error testing method is proposed based on the combination of watt-second method and standard meter method according to the newly published standards, which has high accuracy, stability and reliability. Moreover, the standard energy algorithm can be adjusted more flexibly and perform complex operations at high speed. The researched device can reach 0.05 precision class via verification. Generally speaking, it can not only complete all the tests required by the standards, but also calibrate the accuracy more comprehensively according to the characteristics of the digital electrical energy meter.