The traditional calibration method of electronic transformer usually uses the electromagnetic transformer as the standard source.This method is easy to cause low efficiency and low accuracy of the calibration of electronic transformer,due to the problems of the electromagnetic transformer,which including ferromagnetic resonance,magnetic saturation,difficulties of increasing capacity,complicated two wire connection and the hazard of two open circuit high voltage.And this method faces the problem of direct contrast between analog signals and digital signals.Therefore,a steady-state calibration method of electronic transformer based on the improved digital filtering algorithm is proposed.First of all,the calibration process of electronic transformer is introduced,and this paper analyzes the shortcomings of traditional calibration method of the electronic transformer.Secondly,the paper describes the improved digital filtering algorithm in detail,and proposes a steady-state calibration method of electronic transformer based on the improved digital filter algorithm.Finally,a case verifies the feasibility of the proposed steady-state calibration method,and provides the reference for the large-scale popularization of electronic transformers.