Container loading and unloading system

The invention discloses a container loading and unloading system which comprises a portal frame, the portal frame comprises at least two supporting frames, a main beam and a lifting appliance assembly, the two supporting frames are arranged in a spaced mode in the transverse direction and movably arranged in the longitudinal direction, one supporting frame is used for being arranged on a platform, and the other supporting frame is used for being arranged on the main beam. The other supporting frame is used for being arranged between railway lines. The main beam is supported at the upper ends of the two supporting frames; the lifting appliance assembly is used for conveying the container located on the discharging station to the pre-storing station. The supporting frame is arranged between the railways, the two supporting frames are not arranged on the platforms on the two sides of the railway tracks, the span of the main beam is shortened, the lifting appliance assembly can convey the containers to the pre-st