The invention relates to a hydraulic winch braking device. A brake strap is in an annular shape provided with an opening, a first connection lug plate and a second connection lug plate are fixedly arranged at the opening, the first connection lug plate is hinged to a first corner part of a triangular plate, a second corner part of the triangular plate is hinged to a hinge fulcrum shaft sleeve, a third corner part of the triangular plate is hinged to an output shaft of an oil cylinder, and the end of the oil cylinder is hinged to a supporting seat; a hand-operated brake shaft is sleeved with the hinge fulcrum shaft sleeve and fixedly connected with the hinge fulcrum shaft sleeve, and the thread portion of the hand-operated brake shaft is in threaded fit with a brake nut hinged to the secondconnection lug plate; and an elastic reset device comprises a tight side pull plate, a reset spring seat and a compression spring, the upper end of the tight side pull plate is rotationally connectedwith the triangular plate, the lower portion of the tight side pull plate is rotationally connected with the reset spring seat, and the compression spring is arranged in the reset spring seat. The hydraulic winch braking device provided by the invention can conduct rapid and efficient braking and provide emergency manual braking and is simple in structure, manufacturing and using are both very convenient, the working efficiency is improved, the service life is prolonged, and the work safety and reliability are improved.