The invention discloses a pneumatic automobile crane used for principle demonstration, belonging to the hoisting machinery field, and comprises an automobile chassis, a cargo boom, a revolution mechanism, a hoisting mechanism and a luffing mechanism. The automobile chassis controls front axle deflection steering through a steering cylinder, and provides rear axle driving power through a gas motor; the vehicle frame of the automobile chassis is also provided with two sets of hoisting supporting legs. The revolution mechanism realizes the rotation of a revolving platform through a swing cylinder; the cargo boom is installed on the revolving platform, and a cylinder controls the telescoping of the cargo boom; the hoisting mechanism utilizes a pneumatic motor to drive a reel to fold and unfold a steel wire rope to hoist cargoes; the luffing mechanism controls the inclination angle amplitude of the cargo boom through a luffing cylinder. The pneumatic automobile crane utilizes pneumatic power as the power source of an automobile crane, simulates and manufactures the demonstration model of the automobile crane, more visually displays the work principle of the automobile crane, facilities on-site teaching and principle demonstration, and plays a good role in researching the automobile crane.