Abstract: The method of analyzing the gases evolved from the internal materials of cables is currently receiving significant attention in the field of cable condition diagnosis research. Clarifying the characteristics of gases released from high-voltage XLPE cables under different defect conditions is a fundamental prerequisite for conducting condition diagnosis work. In response to this, several typical fault types of high-voltage XLPE cables, including corrosion of the water-blocking buffer layer, low-energy and high-energy discharge faults in XLPE insulation, as well as low-temperature and high-temperature thermal faults in the buffer layer, XLPE, and semiconductive layer materials, were taken into considerattion, and experimental simulations were conducted to replicate the characteristic gas generation processes of these fault types. Moreover, the variations in the types and proportions of characteristic gases produced by different faults, including CH₄, C₂H₆, C₂H₄, C₂H₂, CO, CO₂, and H₂ were described. Findings suggest that certain fault types can be identified solely by the types of gas produced, while distinguishing other fault types necessitates additional consideration of parameters like gas proportions. This study is expected to provide a new perspective for the state diagnosis of high-voltage XLPE cables, offering data and theoretical supports for assessing cable conditions based on XLPE cable gas production characteristics.