Gearbox of petroleum drilling rig winch and winch adopting gearbox

The utility model relates to a gearbox of a petroleum drilling rig winch and the winch adopting the gearbox. The gearbox is characterized in that two high-power motors obtain transmission ratios of a neutral position and two gears through a dual-input parallel operation gear mechanism and an electric screw rod gear shifting device, a power flow after parallel operation is decelerated through a planetary gear train, through a short-distance single drum-shaped tooth swing coupling mechanism, a movable side is transmitted and moves to a roller spindle and a roller lifting device, so that winch operation is implemented. According to the gearbox, the functions of dual-input parallel operation and gear shifting are implemented, the power speed regulation range is expanded, and the operation efficiency is improved; through the short-distance swing coupling mechanism, the weight and the volume of the gearbox and the winch can be greatly reduced, the cost is reduced, and the winch can be widely applied to an ocean drilling machine; as for the drilling machine above 9,000 meters provided with two gearboxes, safety operation of the winch is guaranteed through the functions of short-distance swing coupling and a clutch mechanism.