In order to calibrate DC power metering modules in the electric vehicle charging pile in the field, developed a field detection device based on source and meter integration design. In the device, the power source module and the standard power metering module shared a set of transducer. In the device, voltage was measured by precise resistance voltage divider, current was measured by zero flux current transformer. In the zero flux current transformer, measuring sensitive parameter for feedback regulation was second harmonic component, which was extracted by secondorder filter and 2 stage amplifier. Designed a distributed synchronous traceability scheme. Evaluated uncertainty of calibration result. The results of calibration and evaluation indicate that the measurement accuracy is most high in the typical charging condition, and satisfy demand in the other charging condition.