In a localized torsional severe plastic deformation method for conical tube metal, a desired region of a conical tube metal can be subjected to severe plastic deformation using molds in which roughness is formed at predetermined regions. The method includes roughening a predetermined region of each of the molds; sticking the conical tube metal only to the roughened regions of the molds; moving the lower mold toward the upper mold to apply a load to the conical tube metal; and rotating the molds to apply severe plastic deformation to the conical tube metal only at the regions stuck to the roughened regions of the molds.