The utility model discloses an oil pumping unit pulling force induction fastening packing device, composed of a fastening disc, a rope, a fixed pulley and a counterweight. The fastening disc fixedly sleeves a packing box of a polished rod; the fixed pulley is arranged on an oil pumping unit rack; one end of the rope is fixed to the fastening disc; the rope winds the fastening disc; the other end of the rope bypasses the fixed pulley and suspends the counterweight. When packings in the packing box are insufficient and can not be used for sealing, the fastening disc on the packing box can rotate under the effect of the counterweight to fasten the packings; the fastening disc on the packing box can rotate a little with the abrasion of the packings, which allows the packing box to be always in a fastening state. The oil pumping unit pulling force induction fastening packing device can automatically fasten packings, reduce wellhead oil leakage caused by insufficiency of the packings, put an end to environment pollution caused by oil leakage, and substantially reduce labor intensity of oil extraction personnel.