The rail type container gantry crane is composed of a main beam, rigid and flexible door legs, a running trolley, a lifting mechanism, a crane running mechanism, an electrical system, and an operating cab. According to the yard operation process, extending the cantilever in the direction of a single or double door leg becomes a single or double cantilever model, and not extending becomes a non cantilever model. Determine different structural forms of non cantilever, single cantilever, and double cantilever based on the site, container storage and transportation process, and loading and unloading vehicles (container trucks or railway vehicles)