Abstract: Converter transformer resin impregnated paper (RIP) bushing is used as a key equipment of the converter transformer to connect the converter valve, and its safe operation is directly related to the reliability of power system. In recent years, there have been several overheating and discharge faults of RIP bushing caused by the deterioration of electrical contact at home and abroad, so it is necessary to analyze the failure mechanism of the electrical contact used in RIP bushing. In this paper, taking the overheating fault of ±500kV RIP bushing as the object, the friction travel of the contacts used in RIP bushing under the actual operating current was calculated. Morphology and composition of the contacts, before and after deterioration, from the surface and cross perspective was analyzed by using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), and finally the degradation mechanism of the electrical contacts was proposed. The study found that the lack of silver plating on the surface of the copper conductor is the main reason for shortening the life of the contacts, and long-term mechanical wear and corrosion of SF₆ gas decomposition products are important factors leading to the deterioration of contacts. The conclusion can provide a theoretical basis on the overheating failure analysis and its protection for RIP bushing.