Necking die for outer containers

The utility model discloses a necking die for outer containers, which comprises a bottom plate. A press plate is fixedly mounted on the bottom plate, through holes are respectively arranged at two ends of the press plate, flat gaskets are mounted on the through holes, a cavity penetrates through the press plate to be fixedly connected with the bottom plate, an ejecting plate is disposed at the bottom of a die cavity inside the cavity, an outer container is placed into the die cavity of the cavity, and a sheath is sleeved on the outside of the outer container in a fastened manner. The necking die is reasonable in structure, simple in operation and fine in operating effect.