Phase calibration is an essential means for daily equipment maintenance in space tracking, telemetry, command(TT&C) system. Generally phasecorrected value of the phase calibration is analyzed through applying software defined radio(SDR).Vector voltmeter is an advanced instrumentation with highprecision, wide band and high sensitivity, which can test amplitude and phase simultaneously. The phase difference of sumdifferential channel is calculated by using vector voltmeter. A novel phase calibration method is realized under the hardware platform. The technique discussed in this paper has been successfully applied in project.