The three-phase circuit power metering is an important content of three-phase circuit analysis, which is discussed in detail in the classification of three-phase three-wire system and three-phase four-wire system, but it does not have a clear statement for the three-phase three-wire watt-hour meters’ own single phase power consumption metering. For this, so this article makes the analyzation from the design of power supply to the different methods of the three-phase circuit power metering, and elaborate the specific verification methods for the power consumption of the three-phase three-wire watt-hour meter according to the actual application requirements and significance.