Multi-shaft linkage connecting device, heavy safety door and water seal safety box

The utility model discloses a multi-shaft linkage connecting device which comprises a door post hinge part, a door frame hinge part, a first rotating shaft, a second rotating shaft and a hinge connecting body, the door post hinge part and the door frame hinge part are installed on a safety door respectively, the hinge connecting body is of an integral solid structure, and a first through hole and a second through hole which penetrate through the solid structure are formed in the two side ends of the hinge connecting body respectively. A first through hole and a second through hole are formed in the upper portion and the lower portion of the door column hinge part, a third through hole and a fourth through hole are formed in the upper portion and the lower portion of the door frame hinge part, and the first rotating shaft penetrates through the first through hole, the first penetrating hole and the second through hole to be installed on the hinge connecting body. The second rotating shaft penetrates through th