A manufacturing method for a wheel disc, includes forming a flange portion, wherein the flange portion is formed such that an inner mold and an outer mold having a cylindrical inner surface with a first inside radius larger than the first outside radius and placed above the inner mold coaxially to the inner mold are brought close relative to each other in an axial direction by one stroke so that the outer edge of the disc material is bent downward, and the cylindrical inner surface of the outer mold is provided with recessed portions hollowed outwardly in a wheel radial direction, the recessed portions being formed in ranges corresponding to the window portions in the wheel circumferential direction and in a range from a middle position to a bottom end in the wheel axial direction.