Cantilever crane is a light, compact and high-efficiency lifting equipment, also often called balance crane, mainly composed of columns, slewing arms, slewing drive devices, electric hoists (or balance hoists) and other main components. It can lift heavy loads in a vertical direction, and can flexibly rotate in the range of 180°, 270° or 360°, and can cooperate with the longitudinal movement of the cantilever to realize material handling and positioning. It is widely used in factory workshops, warehouses, docks, machine tool processing and other scenarios, especially suitable for short-distance and frequent lifting operations, with the advantages of simple structure, convenient operation, small footprint, low maintenance cost, etc., is an ideal equipment to improve material handling efficiency and reduce manual labor intensity.