Abstract: Tension insulator strings are inevitably prone to aging during long-term use, and if not replaced in a timely manner, it will have an impact on the operational safety of transmission lines. This study aims to address the aging issue of insulators in the tension section of 35 kV transmission lines, and proposes the use of non power outage operation technology with operating poles for replacement. In response to the complex terrain and high tension wire working conditions in mountainous areas, the performance of hydraulic and mechanical operating rods is compared, and the hydraulic operating rod combined with insulation tightener scheme is optimized. Through simulation testing, it has been verified that the operation time is controlled within 25 minutes per string, and the insulation resistance is greater than 1000 MΩ, which meets safety standards.