Abstract: This article systematically analyzes the microstructure evolution law, mechanical performance characteristics, and fatigue failure mechanism of the welded joints of 6082 high-strength aluminum alloy scaffold tubes through SEM/EBSD characterization, mechanical performance testing, and finite element simulation, in response to the problem of deteriorating performance of the welded joints. The research results indicate that the grain coarsening and hardness reduction in the heat affected zone are caused by the dissolution of Mg ₂ Si phase, resulting in a decrease in hardness to 60% -75% of the base material; The weld area is formed with fine fish scale patterns through double pulse MIG welding, which suppresses the generation of coarse phases. The welding speed has the most significant impact on the strength of the heat affected zone, and the strength of the heat affected zone decreases to 160MPa at 800mm/min. Based on residual stress numerical simulation and fracture analysis, the low-temperature dual pulse MIG welding+post weld micro arc oxidation composite process showed no significant damage to the welded joint under 200 fatigue cycles, and only stress concentration appeared at the weld toe after 1000 fatigue cycles, indicating that the fatigue life of the welded joint is considerable. The research conclusion provides important theoretical basis for the safe design and process optimization of aluminum alloy scaffolding for high-altitude operations.