A method for manufacturing a bicycle rim includes the following steps. A first bar of material and a second bar of material are formed by extrusion. The first bar and the second bar are respectively made into an arched section of material (unfinished external ring, unfinished internal ring) and cut. Excessive portions of the unfinished external and internal rings are cut from by trimming. The unfinished external and internal rings are assembled and interconnected to each other. The assembled unfinished external and internal rings are laterally pressed to promote a connection between the unfinished external and internal rings. The ends of the unfinished external ring are welded and connected to each other, and the ends of the unfinished internal ring are welded and connected to each other to from a rim structure. Any roughness of the rim structure is ground and the bicycle rim is finished.