Expansion accessory of recreational vehicle

The invention discloses an expansion accessory of a recreational vehicle. The expansion accessory comprises a folding main body, and the folding main body is installed on a vehicle body through an installation base body. The folding main body can move to one side of the vehicle body; after the folding main body is unfolded, a box body structure with an opening can be formed; the box structure comprises a top plate, side plates, a bottom plate, a first end plate and a second end plate. The opening of the box body structure is arranged close to the side surface of the vehicle body, and an accessdoor is arranged on the folding main body; the folding main body is mounted on the vehicle body in an external hanging manner through the mounting base body; in use, the folding main body is unfoldedto expand the use space of the vehicle body, the folding main body is folded after use, or the folding main body is detached and stored so that the normal use of the vehicle body is not influenced, the use space of the vehicl