Elastic positioning pin

The invention provides an elastic positioning pin. The elastic positioning pin comprises a positioning pillar of a vertically through hollow structure. An outwards protruding step is arranged in the middle of the outer wall of the positioning pillar, and a plurality of notches are formed in one side of the positioning pillar in the axial direction with the step as the boundary. The cylindrical surfaces between the adjacent notches form elastic pieces. A limiting rod is inserted into the positioning pillar and in clearance fit with the positioning pillar. When the diameter of a blank hole is the minimum actual size, the elastic positioning pin is in zero-clearance fit with the hole. When the diameter of the blank hole is the maximum actual size, the elastic pieces of the elastic positioning pin can contract along with the hole diameter in the radial direction, so that the elastic positioning pin is in zero-clearance fit with the hole. The problems of an existing positioning pin are solved accordingly.