Abstract: To address the issues of poor universal adaptability, low efficiency, and insufficient material performance in existing closed-type clamps for 330 kV line insulator replacement, standardized structural design and key parameter optimization were conducted. By analyzing the defects of existing clamps, the concept of "universal adaptability for the same tonnage with a single clamp" was established. The structure of the clamp body, clamp cover, and adjustable jaws was optimized, and high-strength lightweight materials were selected. Key parameters were further optimized through finite element analysis and mechanical testing, validated by field trials. The results show that the clamp is adaptable to insulators of multiple tonnages, reduces weight by 40%, doubles replacement efficiency, achieves a static load of 162.5 kN, and maintains a safety factor of ≥2.5. It meets the maintenance requirements for 330 kV lines.