Because aluminum and magnesium alloys,which have been widely used in aerospace and electronics,are difficult to achieve ultra-thin plate welding,a micro friction stir welding machine based on Mach3 control system was designed. For the welding operation using this equipment,the stirrer with a shoulder that diameter was 6～8 mm could be used for the welding of thin plates（≤1 mm）,and the 3 D forming micro friction stir welding could be completed. There was a small amount of heat input in the welding process,small deformation occurred and the appearance of weld was great. The Mach3 control system is excellently compatible,applicative,and stable.It is easy to operate,maintain and open. The micro friction stir welding machine is small in size,light in weight and easy to install. The welding machine is available with high welding stability and operability.