Method for measuring tail shrinkage length of aluminum alloy bar and application of method

The invention discloses a method for measuring the tail shrinkage length of an aluminum alloy bar and application of the method, and relates to the technical field of aluminum alloy extrusion detection. Wherein the aluminum alloy bar is obtained by extruding an aluminum alloy cast bar through a forward extrusion process, during extrusion, the aluminum alloy cast bar sequentially flows through an extrusion cylinder and an extrusion die, extrusion is stopped at the final stage of extrusion, and extrusion residue is reserved in the extrusion cylinder; the measuring method comprises the following steps: respectively measuring or acquiring the rod diameter of the aluminum alloy rod, the length of the aluminum alloy cast rod, the barrel diameter of the extrusion barrel, the rod diameter of the aluminum alloy cast rod and the thickness of the extrusion residue; and then the tail shrinkage length is calculated. Based on the measuring method, a large amount of tail shrinkage length verification and batch inspection wo