Multi-working-condition brake hydraulic system for dispatching winch

The utility model discloses a multi-working-condition brake hydraulic system for a dispatching winch. The multi-working-condition brake hydraulic system comprises an oil tank, an oil supply way and a brake oil way. An oil suction filter, a gear pump, a high-pressure filter, a one-way valve, an electromagnetic directional valve and a brake oil cylinder are sequentially connected in series on the oil supply oil way; the brake oil way is divided into three parallel branches, namely a first-stage brake oil way, a second-stage brake oil way and a third-stage brake oil way; a first electromagnetic ball valve and a proportional overflow valve are arranged on the first-stage brake oil way; a second electromagnetic ball valve and a throttling valve are arranged on the second-stage brake oil way; the throttle valve is connected in parallel with the backpressure overflow valve; a third electromagnetic ball valve and a fourth electromagnetic ball valve are arranged on the third-stage brake oil way; the tail end of the br