Abstract: This invention relates to a method for molding a bicycle tube and the method comprises the following steps: first, providing a tube and then controlling thickness of the tube by a drawing and extruding process for forming a molding portion. Second, plasticize other portions of the tube into particular diameters and shapes by plasticizing processes. Third, hydroform the molding portion of the tube by a mold and a hydroforming device for forming particular three-dimensional shapes. By applying to the above-mentioned method, the tube could be molded into a three-dimensional, unique and delicate shape.