Longitudinal box body outer cargo supporting structure based on truck with loading crane

The longitudinal box body outer cargo supporting structure based on the truck with the loading crane is provided with a cargo carrying carriage, and welding outer beams which are in bilateral symmetry are installed at the bottom of the cargo carrying carriage in the length direction of the carriage; sliding supporting inner beams are installed in the welding outer beams which are symmetrical left and right in a drawing and sliding fit mode. A limiting locking device and a grease nipple are mounted on the welding outer beam; the limiting and locking device is used for limiting and locking the drawing position of the sliding support inner beam; the grease nipple injects lubricating oil into the sliding side surface of the sliding support inner beam; the tail end of the outer side of the sliding supporting inner beam is fixedly connected with a beam assembly and a pull ring. The technical problem that a lorry-mounted hoisting transport vehicle cannot meet the extensible safety support requirement of large object