Abstract: Insulation sheath of high voltage power cables is a crucial component of cable system, and its quality directly impacts stability of power supply and lifespan of cables. In the paper, causes of insulating sheath ablation of high voltage power cables were analyzed, and corresponding solutions were proposed. Through theoretical analysis and simulation calculations, impact of factors such as grounding circulation, ground potential, and grounding resistance on sheath ablation was explored. Results showed that main reasons of ablation were excessive metal sheath circulation, floating voltage, and increased grounding resistance. Changes in sheath voltage under different grounding conditions were verified through simulations, and solutions including reducing metal sheath circulation, minimizing floating voltage, enhancing online monitoring, and improving operational management were proposed, which could provide scientific guidance for design, installation, and maintenance of cable lines, ensure safe and stable operation of high voltage cables.