The invention discloses a combined high-voltage cabinet, and belongs to the technical field of high-voltage cabinets. The high-voltage cabinet comprises a top plate, a bottom plate, a back plate and two side plates, the tops of the two side plates are both matched with the top plate in an inserted mode, the bottoms of the two side plates are both matched with the bottom plate in an inserted mode,the bottom of the back plate is matched with the bottom plate in a lap joint mode, one side of the back plate is attached to the two side plates, the top plate, the bottom plate, the back plate and the two side plates form a containing cavity, two cabinet doors for sealing the containing cavity are arranged at the front end of the containing cavity, one cabinet door is hinged to one side plate, the other cabinet door is hinged to the other side plate, and a placing piece is arranged between the two side plates and matched with the two side plates in a lap joint mode. When a first baffle or other parts are damaged in the conveying process, the combined high-voltage cabinet can be mounted and spliced in time by disassembling and replacing the first baffle with a new first baffle, and the back plate, the top plate and the two side plates are stacked on the bottom plate in sequence in the conveying process, so that the space can be reduced, and transportation is facilitated.