The invention discloses a reverse hitting preparation technology of a prefabricated self-insulation wall body. The wall body comprises a concrete wall body, an insulation board and a cement mortar layer protective layer, wherein the insulation board is arranged at the outer part of the concrete wall body; the insulation board is provided with a protective layer; and the cement mortar layer protective layer is arranged at the outer part of the insulation board. The prefabricated self-insulation wall body is produced through an insulation board reverse hitting construction technology, and connecting pieces of outer hinge plates in an original sandwich structure and the interior and exterior are discarded, so that the cost is greatly reduced, the production efficiency is improved, selfweight of buildings is decreased, and large-scale popularization of the prefabricated buildings is guaranteed.