The invention provides an electronic transformer with a self-calibration function. The electronic transformer comprises a sensing head, a signal processing unit, a merging unit, a standard direct current power supply, a multipath switch, a control unit and a calibration module. A standard direct current voltage source is used for outputting a standard signal with a known amplitude and a phase under a calibration mode. The multipath switch is used for switching between the sensing head and the standard direct current voltage source. The control unit is used for making the multipath switch be switched to a standard direct current voltage source side. The calibration module is used for comparing a standard-source detected value calculated and acquired by the merging unit to a standard-source theoretical value so as to acquire a ratio difference and an angle difference of the electronic transformer. The self-calibration function of the electronic transformer is realized and/or whether an acquisition circuit in the signal processing unit works normally is determined.