Abstract: On the base of the introduction of the method and principle of the new concept of friction flow welding,one of the variant of friction stir welding,the fundamental research of this welding process was conducted by regarding to the weldability of the different aluminum alloys and the adaptability of various part structures.The testing results show that friction flow welding can get reliable solid state joint within limited thickness by diffusing of the heat plastic flow of the metal material generated by the purposed designed welding tool without central pin.This welding process can be used in joining the butt and lap joints of the thin gauge panel structures,repairing surface defect,filling keyhole and modifying surface performance.