Abstract: With the wide application of low-smoke halogen-free polyolefin outer sheath cables, the repair of damaged outer sheath becomes the key to ensure the performance and life of cables. Focused on cold shrinkage low smoke halogen-free polyolefin jacket repair scheme.Through the deep analysis of the material characteristics and structural design principle of repair scheme, mechanism of action was clarified. Using variety of test methods, including compatibility test, waterproof test, long-term aging test, resistance to external impact test, shrinkage test at incision after high and low temperature switch, anti-UV test, immersion test after aging, vibration test, bending test to verify that repaired cable in oil, immersion, thermal aging, ultraviolet light exposure, external force, hot and cold alternating incision displacement, immersion after aging, external vibration, bending subjected. Reliability of continuous operation under 9 kinds of external environmental conditions. Based on various test data, the cold-shrink low-smoke halogen-free polyolefin outer sheath repair scheme had high reliability, had significant application value in improving the stability of cable system, and also provided an important reference for the subsequent optimization and development of related repair technologies.