Abstract: The Al6005 welded joint was treated with ultrasonic impact and the residual stress of the treated and untreated specimens was measured. The results showed that uniform compressive stress distributed in the weld and heat-affected zone(HAZ) after the joint was treated with ultrasonic impact. The properties of welded joint were discussed after salt spray corrosion test. The results indicated that the treated joint produced less corrosion product after corrosion for different times. The hardness of the weld metal and HAZ increased after the joint was treated with ultrasonic impact. The thickness of hardened layer in the weld metal and HAZ was 1.5 mm and 2.1 mm, respectively. The thickness of hardened layer maintained at 0.9 mm after corrosion for 14 days. Besides, the welded joint after treatment could have better mechanical properties than untreated joints.