The invention discloses an on-site initiative error-verification system for a voltage transformer and a method thereof and relates to a voltage transformer verification system. The system comprises a personal computer (PC) (10), a wireless program control voltage regulator (20), a voltage booster (30), a series resonance circuit (40), a standard voltage transformer (50), a detected voltage transformer (60), a wireless program control transformer calibrator (70) and a wireless program control load box (80). The method comprises equipment parameter input, verification parameter setting, booster circuit prediction, prediction result judging, automatic measurement of errors and finishing. According to the system and the method, manual control is replaced by computer control, automation of the on-site voltage transformer verification process is achieved, and on-site verification working efficiency is improved. The verification system can automatically judge an actual load of a booster circuit, works out resonance parameters, monitors each parameter in real time and performs protecting control, and improves safety of on-site verification work.