Gear box of petroleum drilling machine winch and winch adopting gear box

The invention relates to a gear box of a petroleum drilling machine winch and a winch adopting the gear box. Double high-power motors obtain transmission ratios of a neutral gear and two gears through a double-access parallel operation gear mechanism and an electric lead screw gear shifting device; the power after the parallel operation flows through a planet gear mechanism for decelerating; and a short-distance single-drum type tooth swing connecting mechanism transfers a moving edge and a motion to a roller shaft and a roller lifting device so as to achieve the winch operation. The gear box achieves a double-access parallel operation gear shifting function, widens the power speed adjusting range, and improves the operation efficiency; the short-distance swing connecting mechanism largely reduces the weights and the sizes of the gear box and the winch, reduces the cost, and can be widely applied to a marine drilling machine; and for a drilling machine above 9000 m having two gear boxes, the safe operation of the winch is guaranteed through functions of a short-distance swing connecting and clutching mechanism.