Disclosed is a working bucket leveling mechanism of a hydraulic aerial cage. The mechanism comprises a working bucket, a linkage component, integrated hydraulic system components and a cantilever crane. A telescopic hydraulic cylinder is adopted as a leveling execution element of the leveling mechanism, and the working bucket, the linkage component, the integrated hydraulic system components and the cantilever crane are hinged together through hinges. Each integrated hydraulic system component is a small independent hydraulic system and composed of a servo motor, a two-way gear pump, a safety overflow valve, a one-way throttle valve, a hydraulic control one-way valve, a balance valve and a hydraulic cylinder. The flow and flow direction of hydraulic oil are controlled by the integrated hydraulic system components through the servo motors, and the rotating speed and steering direction of the servo motors are controlled through electric signals of a tilt angle sensor. The two integrated hydraulic system components are controlled by one controller in a unified manner, so that synchronous running of the hydraulic cylinders is achieved. The working bucket leveling mechanism is simple in structure, convenient to arrange, high in work efficiency, fast and stable in leveling and convenient to demount and maintain.