Friction stir welding technology has been successfully crossed the experimental research stage.It is the practical technology of connection industrialization to replace welding technology,which is widely used in high-speed rail,aerospace and pipe welding processing and reveals a significant technical advantage and economic benefits.A kind of suction type friction stir main spindle structure was designed driven by servo electric cylinder,in the premise of matching welding processing technology， it could turn to CNC machining center spindle after a simple transformation.The structure greatly expands the application scope of equipment by flexible change and a large number of equipment procurement costs are saved.