Abstract: The present invention pertains to a method of manufacturing a bi-metal screw comprising a sequence of procedures; wherein, the process preparation is for arranging a shank portion and a drilling portion made of different materials; the shank portion has a planar welding surface defined thereon; in particular, the drilling portion includes a conical section with a conical surface defined on the top face thereof. While operating, the conical section is gradually welded to the planar welding surface to form a composite screw, so as to smooth the air away for preventing the interspaces generated within the junction of the two portions and rendering the composite screw not to be slanted aside. Subsequently, an integral bi-metal screw is formed through the processes of precisely cutting and formation, thereby increasing the quality of the screw.