Abstract: Aiming at the 3 mm thick 6061 aluminum alloy plate, the influences of friction stir welding process parameters on the quality and performances of the joint were studied. The pressure of the shaft shoulder mainly affect the joint appearance, the rotational speed and the welding speed mainly affect the joint quality. By changing the above parameters, the change of the joint appearance and the tensile strength were observed and analyzed. The results show that when the pressure of the shoulder is 0.2 mm, the surface of the weld is good, the defect is less and the tensile strength is high. When the rotational speed of the stir is high or the welding speed is low, the appearance of the joint is good. When the rotational speed is 950 r/min and the welding speed is 37.5 mm/min, the welded joint has the highest tensile strength. Under the condition of the proper match between rotational speed and the welding speed, the welded joints with high tensile strength can be obtained.