The invention relates to a detachable prefabricated wall mold. The detachable prefabricated wall mold comprises a first module, a second module, a third module and a fourth module which are assembledtogether through positioning pins and bolts, and fixed on a workbench so as to form the detachable prefabricated wall mold, wherein a crack is left among the first, second, third and fourth modules after the assembly; a water-stop steel plate is mounted in the crack; through three positioning blocks welded onto the third module, the first, second, third and fourth modules are positioned and connected with the water-stop steel plate; each of the first, second, third and fourth modules is formed by welding an upper horizontal plate, a lower horizontal plate and rib plates arranged on two sides;and reinforcing rib plates are welded into the second and third modules along the vertical direction. By adoption of the detachable prefabricated wall mold provided by the invention, the constructionrequirements for various wall length specifications can be met; the problem that the length of a conventional mold can be modified only through cutting can be solved; a lot of steel and manpower can be saved; the construction period can be shortened; and greater economic benefits can be achieved.