Abstract: In order to improve the efficiency of replacing tension-resistant synthetic insulators for transmission lines and ensure that the replaced tension-resistant synthetic insulators meet the requirements of transmission line engineering standards, an auxiliary tool for replacing tension-resistant synthetic insulators is developed. The tool mainly includes three parts: hook unit, link unit and main unit. Before the maintenance personnel replace the tensioning insulator, they should connect the side of the tower and the side of the wire through the hook unit. During the replacement process, they should ensure that the maintenance personnel sit firmly on the main unit to replace the tensioning insulator, and at the same time rely on the connection unit to effectively connect the hook unit to the main unit. The experimental results show that this auxiliary tool can effectively improve the quality of transmission line tension synthetic insulators replacement, improve the replacement efficiency and equipment management level, and has a good value of popularization and application.