The invention relates to a hydraulic staircase control system for a large-sized dump truck. The hydraulic staircase control system comprises a solenoid valve, a hydraulic staircase control cylinder, a buzzer, a declining state indicator lamp, a declining limit indicator lamp, a parking delay, a first knob switch, a second knob switch, a first lifting limit relay and a second lifting limit relay. The hydraulic staircase control system has the advantages of being simple in structure, reliable in work, convenient to operate and low in manufacturing cost, and the safety of working personnel and the large-sized dump truck is favorably ensured. By the use of the hydraulic staircase control system, when a staircase is in a declining state, the working personnel can conveniently get on and get off the dump truck; when the dump truck is in a driving state, the staircase is in a lifting position, so that the collision of the staircase with a pavement is favorably avoided, and the probability of damage is low.