Laser welding has excellent welding quality and high efficiency， and has partly replaced the traditional arc welding process. The development of hand-held laser welding technology improves the flexibility of operation， therefore greatly increasing its industrial acceptance. To further improve the repair level of aluminum alloy fittings for ultra-high voltage transmission lines， the repair feasibility of hand-held laser welding technology was studied， the influence of parameters such as laser power， beam swing mode， and swing amplitude on the repair effect and morphology were studied， and the tensile strength and electrical conductivity of respective repaired joints were tested. Results show that using the hand-held laser welding technology， a well-formed repair layer can be obtained when the beam is in the "—" swing mode. There are multi-pass microstructure characteristics in the repair layer， and the grains in the middle of the weld are relatively small， and the grains near the base metal are larger. With appropriate range of laser power and swing amplitude， linear repair can well repair small crack-like linear gaps at one time. The tensile strength of the repaired joint is not lower than that of the base metal， and the electrical conductivity can reach 89.43% of the base metal， and the hardness is higher than that of the base metal. In summary， the use of hand-held laser wire filling welding can realize the repair of aluminum alloy power transmission fittings， and it reveals significant prospects to be used for repairing gaps in ultra-high voltage transmission line fittings.
