Closed hydraulic oil way of hoister

The utility model relates to a closed hydraulic oil way of a hoister, which is characterized in that a brake hydraulic pump is additionally arranged on a mechanical connecting link of a diesel engine and a bidirectional hydraulic pump, a spindle of the brake hydraulic pump is connected with a spindle of the bidirectional hydraulic pump and a spindle of the diesel engine by the aid of mechanism drive, an oil inlet of the brake hydraulic pump is connected with an oil outlet of a hydraulic oil tank, a hydraulic oil is sucked from the hydraulic oil tank, and extracted oil of the brake hydraulic pump is connected to the hydraulic oil tank by the aid of an overflow valve. By measuring incremental speed of the diesel engine towed by the driving torque of the bidirectional hydraulic pump, the throttling functions of the brake hydraulic pump and the overflow valve are controlled, so that driven torque of the brake hydraulic pump balances the driving torque of the bidirectional hydraulic pump, and the closed hydraulic