Mechanical arm for car model selling

The utility model discloses a mechanical arm for selling car models, which belongs to the technical field of mechanical arms and comprises a connecting base, a first rotating arm is arranged on the connecting base, a second rotating arm is rotatably arranged in the first rotating arm, and a rotating extension frame is rotatably arranged in the second rotating arm. According to the mechanical arm for car model selling, by arranging a contact plate, a second elastic assembly, a first elastic assembly, a piston barrel, a first piston plate, a second piston plate, a piston frame, an extrusion plate and a control switch, the first piston plate is extruded to move in the piston barrel, meanwhile, the second elastic assembly is extruded, the car model clamping process is softer, and the car model selling quality is improved. Meanwhile, after the car models are clamped to a certain degree, increased air pressure in a piston frame automatically controls an extrusion plate to extrude a control switch, so that a thread