The invention relates to a portable field calibration system of an electric energy meter. The system comprises a signal acquisition unit. A voltage sensor and a current sensor are connected with the signal acquisition unit electrically. A collected standard voltage signal and a collected standard current signal are transmitted to a signal detection unit; and a calibrated electric energy meter outputs a pulse signal to the signal acquisition unit. The signal acquisition unit is connected with a calibration platform electrically; the calibration platform compares the standard voltage signal and the standard current signal with the pulse signal emitted by the calibrated electric energy meter, thereby calculating an error of the calibrated electric energy meter. According to the portable field calibration system provided by the invention, because the voltage sensor and the current sensor employ open type structures, a running electric energy meter can be calibrated accurately under the circumstances that normal operation of the power system is not affected.