Abstract: The harmonic transfer characteristics in the distribution network are analyzed from two aspects of harmonic current and harmonic voltage. The transfer law of harmonic current in the same and different voltage level systems is analyzed by formula. The analysis results show that the harmonic current mainly flows into the upper system when the filter device is not input. The transmission coefficient is related to the transformer ratio when the wave current is injected into the upper system and transmitted from the low pressure side to the high pressure. The transmission process of the harmonic voltage of the upper power grid to the load side of the power grid is analyzed in detail and the conclusion is drawn. The harmonic voltage of the higher-level power grid is mainly concentrated on the load equivalent impedance of the current-level power grid when passing through the distribution network. When the harmonic filter voltage of the upper-level power grid is mainly transmitted, the system is mainly concentrated on the system of the current-level power grid. The accuracy of the conclusions is verified by numerical simulation.