The existing transformer calibrator has many problems such as, low accuracy, poor stability, error interference of frequency conversion, small range of working circuit, etc., this paper focus on those problems, adopting adjustment technology of rectangular coordinate system and polar coordinate system, automatic measurement feedback technology with high accuracy, desighs an adopable digital program-control standard signal source with two channels of phase and amplitude, realizing aotumatic feedback of phase and amplitude after the frequency and load changing, realizing the aotumatic verification and calibration of transformer calibrator and PT secondary drop test instrument. The device designed in this paper has already passed the test of third-party detection mechanism, all of the technical indexes and function meet the demand.