In recent years, the high-voltage XLPE cable buffer layer ablation problem has been a common occurrence. Currently, the usual option is to directly replace the original cable, but this will result in large financial losses. The paper focuses on buffer layer ablation treatment technology and investigates the efficacy of the cable buffer layer ablation inhibitor. Firstly, the effect of concentrated leakage current on buffer layer ablation was studied, and the principle of inhibitor action was explained from the perspective of ablation mechanism. At the same time, requirements for the physicochemical properties of inhibitors were proposed; Secondly, A cable ablation simulation experimental platform has been established to demonstrate the effectiveness of inhibitor; Thirdly, based on the typical structure of 110 kV cables, a finite element simulation model was established to analyze the electrical characteristics before and after adding inhibitors to the cables. The results showed that after adding inhibitors, the field strength and temperature of the buffer layer became uniform, and local hot spots were eliminated; Finally, the effectiveness of the proposed method was verified through experiments, which showed that the inhibitor can eliminate local heating in the buffer layer.