Abstract: Aero-engine aluminum alloy blade body and gib were welded by friction stir welding (FSW), and the effect of different process parameters on weld seam formation. The results show that aluminum alloy blade body and gib lock bottom structure with single and double side connection could be achieved by friction stir welding technology, and the deformation of the boss front of the gib was very small. The higher the rotation rate of the stirring tool, the easier the hole-type defects appearing on the top of weld seam, and the lower the rotational speed of the stirring tool, the more serious the deformation of the boss front of the gib. The faster the welding rate, the easier, the hole defects appearing on the top of weld seam and the tunnel hole defects appearing on the bottom of weld seam, and the deformation of the boss front of the gib also was relatively large. Defect-free aluminum alloy blade body and gib locked bonding joint could be obtained with the rotation rate of 1 000 r·min-1 and welding rate of 100 mm·min-1, also the deformation of the boss front of the gib was the minimum.