The skeleton trailer is a kind of container carrier semi trailer frame. The frame type vehicle is welded by the longitudinal beam, beam and front and back end beam. The longitudinal beam is made of steel plate 16MN submerged arc welding into I-shape, the beam is made of steel plate stamping into groove, and the front and rear end beam is welded rectangular section. An integral long beam is arranged in the middle part of the container locking device to improve the bearing capacity of the container locking device.