The utility model discloses a card is prevented falling by packing box gland for beam -pumping unit, including the clamp of a pair of semi -ring shape, two clamps concatenations circularize the columnstructure, and two clamps are connected with the rubber pad through a pair of hasp structure detachable connections removablely on the inside wall of every clamp, are provided with a plurality of onthe inside wall of rubber pad and prop up supporting bench along what the lateral wall of rubber pad length direction being used for of distributing and polished rod offseted, the utility model discloses when using, at first with the polished rod rebound of packing lid along the beam -pumping unit in, then on compressing tightly the polished rod of the packing lid below after the removal after through the locking of hasp structure with two clamps, so, the utility model discloses can effectively realize the support to the packing lid, can avoid the packing lid to follow the eminence landing andget off, and then can avoid because of the phenomenon that the gliding of packing lid appears hurting sb. 's feelings, simultaneously the utility model has the advantages of it is convenient with polished rod locking.