This paper summarizes the development trend of civil aircraft power supply system, aiming at the variable frequency AC power supply system, the significance of the research on calibration technology of the test system for civil aircraft variable frequency AC power supply characteristic is expounded. According to the technical requirements of the test system for the characteristics of variable frequency AC power supply, the calibration method is studied and the calibration specification is written; Based on the technologies of Direct Digital Frequency Synthesis (DDFS), Direct Digital Waveform Synthesis (DDWS), broadband signal amplification and filtering, the calibrating signal source for the characteristics of variable frequency AC power supply is developed; According to the workflow and signal setting in the calibration method, the calibration program is made and the automatic calibration system is formed. Finally, the above calibration system is applied to the power supply test systems of several main engine plants and institutes, and the field test verification is completed. Through the above research process, a complete calibration capability of civil aircraft power supply characteristics test system is established, which lays a solid foundation for the future research of civil aircraft power supply characteristics and power supply adaptability of electrical equipment.