Full-automatic leveling system for lifting machine

The invention belongs to the technical field of leveling control over lifting machines, and particularly relates to a full-automatic leveling system for a lifting machine. The full-automatic leveling system is of a novel hydraulic system structure designed for solving the problem that after automatic oil supplement and exhaust, the lifting machine is still not level, and through the structure, leveling can be completed automatically. The full-automatic leveling system comprises a first proximity switch, a second proximity switch, main oil cylinders, auxiliary oil cylinders, booster cylinders and an oil supply part of the oil cylinders; and the oil supply part is connected with rodless cavities of the booster cylinders and rodless cavities of the main oil cylinders through booster cylinder solenoid valves and main oil cylinder solenoid valves. The full-automatic leveling system is structurally characterized in that the inner walls of cylinder barrel guide sleeves of the main oil cylinder, the auxiliary oil cyl