The utility model belongs to the technical field of beam-type pumping unit pumping in the oil field machine pumping, and relates to a polished rod anti-collision device, in particular to a device preventing a polished rod from colliding with a pumping unit horsehead. The polished rod anti-collision device is composed of a polished rod positioning chuck, a supporting rod, centralizing rods and an adjusting jackscrew. A central screw hole is formed in the supporting rod, and the adjusting jackscrew is installed in internal threads of the central screw hole. Two centralizing rods horizontally perpendicular to the supporting rod are symmetrically welded to the two sides of the central screw hole of the supporting rod. Two symmetrical lug holes are formed in the polished rod positioning chuck, and the polished rod positioning chuck is mounted on the centralizing rods in a plugging mode through the lug holes. The polished rod anti-collision device has the advantages that the polished rod is centralized, the accuracy of the indicator diagram acquisition is improved, the polished rod is prevented from colliding with the pumping unit horsehead, the stability of the oil pumping unit operation is improved, and the service life of an oil pumping unit is prolonged.