Abstract: This paper describes in detail the principle of a hydraulic winch and related electrical protection. Keywords: Mine explosion-proof hydraulic hoist, working principle. The mine explosion-proof hydraulic hoist consists of mechanical, hydraulic transmission, and electrical components. It uses a squirrel-cage type explosion-proof main motor to drive a bidirectional variable main oil pump. The main oil pump and two internal curve low-speed high-torque hydraulic motors form a closed-loop, torque-balancing hydraulic speed regulation system. The two hydraulic motors are respectively arranged on both sides of the main unit and connected to the main unit, driving the hoist. The hoist has two auxiliary oil pumps, one working and one on standby. Among the auxiliary oil pumps, the larger pump acts as a replenishing pump, supplying oil to the main hydraulic transmission; the smaller pump is used for control, supplying oil to the braking system, operating system, and rope adjusting system. The hoist adopts a remote hydraulic control operation. The operator inputs pressure oil from low to high into the proportional cylinder of the main oil pump by operating a hydraulic proportional pilot valve, causing the stroke regulator of the main oil pump to activate, changing the tilt angle of the main oil pump's oscillating cylinder to change the flow rate of the main oil pump, thereby changing the speed of the hydraulic motor, starting the hoist, and accelerating its operation. The operator can adjust the main oil pump's output flow rate by manipulating the hydraulic proportional pilot valve handle to different angles, resulting in varying lifting speeds for the hoist. The lifting speed is maximum when the handle is at its maximum position. The hoist stops when the handle is in the neutral position. Reversing the handle reverses the hoist's direction. The hoist uses disc brakes for both normal and emergency braking. Normal braking force is generated by the hydraulic transmission system itself. During lifting, the load becomes the braking force. When lowering a heavy object, the hydraulic motor becomes a pump, and the hydraulic pump becomes a hydraulic motor, generating feedback braking. The disc brake does not participate in working braking; it is only used as a safety device after the hoist drum stops. In case of a malfunction during operation, the safety device automatically engages, or the operator can use a foot switch for emergency braking. The disc brake is open when there is pressurized oil in the lifting braking system and closed when there is no pressurized oil. The hydraulic proportional pilot valve operated by the driver has four pressure-reducing valves. Two of these valves control the forward and reverse oil supply of the main oil pump, while the other two control the opening and closing of the disc brake. When the driver operates the hydraulic proportional pilot valve, two valves are simultaneously pressed down. The pressure oil output from one valve enters the proportional cylinder of the main pump, causing the main pump to supply oil to the hydraulic motor and operate it. The pressure oil output from the other valve supplies the hydraulically controlled directional valve of the braking system, causing the braking system to supply oil to the disc brake, opening the disc brake and allowing the hoist to operate. When the driver returns the handle of the hydraulic proportional pilot valve to the neutral position (the proportional cylinder returns to the neutral position), the flow rate of the main pump gradually decreases to zero, and the hydraulic motor stops operating. At the same time, the hydraulically controlled directional valve resets due to the lack of pressure oil, and the hoist brakes. This ensures that the disc brake opens simultaneously when hoisting starts and immediately engages when the hoist stops, guaranteeing the safe operation of the hoist. The hoist is equipped with comprehensive safety protection functions, including protection against overload, overwind, overspeed, failure to decelerate at the deceleration point, brake shoe wear, high-pressure oil overpressure, insufficient oil replenishment, short circuit, open circuit, and zero position faults. It also features oil temperature and level signals. The hoist has a microcomputer-controlled, intrinsically safe, explosion-proof integrated backup protection device. It includes protection for lifting depth, speed display, overspeed, failure to decelerate at the deceleration point, overwind, and depth indicator failure, as well as backup protection functions such as lifting signal display, memory, and lifting hook count calculation.