High-rotation speed friction stir welding machine and water mist cooling device were designed. The experimental result shows that the butt welding test of 1 mm 6061-T6 sheet aluminum alloy was carried out successfully. Under the condition of highrotation speed and small plunge depth（0.08 mm）,the forward force increases with the increase of rotation speed and the welding speed,and the maximum value is not more than 70 N. The relationship between side force and welding speed and rotational speed is not obvious,and its maximum value is not more than 60 N. The axial force increases with the increase of shoulder width,but decreases with the increase of pin length,and its maximum value is not more than 2.5 kN. The tensile strength of the joint was 265 MPa which come to87.2% of the base metal,when the rotation speed was 15 000 r/min and the welding speed was 100 mm/min.