Abstract: To investigate the gas radial diffusion behavior resulting from gas production in cable buffer layer defects, this study developed a two-dimensional finite element model to analyze the gas diffusion characteristics of buffer layer defects at 90 ℃. The diffusion behavior was compared with that of gas production in insulation shielding layer defects. Additionally, the diffusion behavior of gases in the cable under different operating temperatures was explored. The results demonstrate that: The gas diffusion patterns of buffer layer defects and insulation shielding layer defects are highly consistent, with hydrogen achieving concentration equilibrium rapidly in both the buffer layer and the insulation shielding layer within a short time frame. Furthermore, the gas diffusion rate increases significantly with rising cable operating temperatures.