The invention discloses a forming method of a crankshaft isolation belt wheel shell with a multi-wedged-tooth structure and a mold set. The forming method comprises the steps that inward grinding pushis conducted at the circular corner transition position of a cylindrical part with a long flange by a rotary grinding rotating wheel, so that an inner side web plate forming part is obtained; the outer side of the cylindrical part with the long flange is subjected to flanging operation, a material is squeezed to conduct axial and radial flowing movement, and a convex rib forming region which is preliminarily formed and a rotary tooth forming region which is preliminarily formed are obtained on the outer wall of the cylindrical part; the convex rib forming region and the rotary tooth forming region of the flanged outer wall of the cylindrical part are further reshaped, so that a convex rib structure is obtained; and further machining is conducted in the rotary tooth forming region so thata tooth-shaped structure with multiple wedged teeth can be obtained. According to the forming method, the rotary grinding technology is adopted to form an inner cylinder web plate of a part with the features, the web plate structure is formed at the circular corner transition position of the inner hole flanged part under the action of radial feeding of the special rotary grinding rotating wheel inthe forming process, the formed planarity of the inner cylinder web plate structure is high under the action of radial feeding of the rotating wheel, and the working time of part turning machining can be remarkably shortened.