Abstract: Friction stir welding(FSW) of aluminum alloy usually results in a special " funnel shaped" temperature field, which makes obvious difference of microstructure properties in the direction of weld seams. In order to get better properties of welded joints, ultrasonic stir hybrid welding technology has been put forward in this paper, which concentrates the ultrasonic energy in deep weld seams through the stirring pin. Thickness of 2.5 mm 2219 aluminum alloy sheets has been adopted and welded by the two technologies mentioned above in this experiment, microstructure and mechanical properties of weld are analyzed and compared as well. Result shows that the weld joints of 2219 aluminum welded by the two technologies are both with good appearance and defect-free in the inner, and ultrasonic stir hybrid welding obviously has better mechanical properties.