Abstract: To understand the changes in insulation properties of cross-linked polyethylene(XLPE) cables after short-term high-temperature operation, we investigated the changes and correlation between the aggregated structure and dielectric properties of short cable samples subjected to short-term high-temperature aging. First, we carried out high-temperature aging for 2 days at 90, 105, 120, 35, and 150 ℃ for 10 kV XLPE cables, and then thermally treated at 90 ℃ for 90 days. Finally, the electrical properties of the samples before and after thermally treated were characterized by polarization and depolarization current test and breakdown voltage test, and the physical and chemical properties of the samples before and after thermally treated were characterized by differential scanning calorimetry and Fourier transform infrared spectroscopy. The results show that when the cable experiences short-term high-temperature operation, if the short-term high temperature is within the range of XLPE melting temperature, the interfacial polarization strength and antioxidant consumption rate of insulation will be reduced; while when the short-term high temperature exceeds the XLPE melting temperature, the interfacial polarization strength and antioxidant consumption rate of insulation will increase. The results show that when it is in the XLPE melting temperature range, the subsequent thermal oxygen aging process of the cable is slowed down by the recrystallization effect of the XLPE; when the short-term high-temperature operating temperature of the cable is above the XLPE melting temperature range, the subsequent thermal oxygen aging process of the cable is facilitated by the thermal cracking of the XLPE.