Due to the hysteresis characteristics of the reactor core, residual magnetism will be retained, which is easy to lead to magnetic saturation of the core and generate excitation inrush current, which may cause the differential protection of the power system to operate incorrectly and shorten the life of the reactor if it occurs frequently. In view of the above problems, this paper proposes an attenuation oscillation demagnetization method for the iron core reactor based on the multivoltage rectifier charging and discharging circuit. Firstly, the principle of attenuation oscillation demagnetization is illustrated through theoretical analysis, and the parameter selection of energy storage capacitors is determined, followed by the analysis of the principle of doubled-voltage rectifier circuit and the simulation to verify the effect of the combined demagnetization of doubled-voltage rectifier power module, and finally the experimental verification and determination of the multiple-voltage rectifier-based attenuation oscillation demagnetization of iron core reactors.