The utility model discloses a riveting fixture for powder metallurgy crankshaft, which comprises a base for mounting powder metallurgy crankshaft, and a powder metallurgy crankshaft placed on the base, the part of the single shaft to be riveted slightly extends out of the surface of the powder metallurgy structural component, a top plate is arranged above the powder metallurgy crankshaft, a punch is mounted at the lower bottom surface of the top plate, an elastic support reset structure is arranged between the top plate and a bottom plate, and a limit device is arranged in the motion stroke of the punch. The loose problem of the single shaft and the powder metallurgy structure component is successfully solved during the high speed load working process, the mechanical performance of the powder metallurgy structural component is guaranteed and the service life thereof is also improved.