The invention provides a light wall slab, which is producing by the following materials in weight percentage: 30 percent of slag with the grain size of less than 8mm, 35 percent of fly ash with the pellet diameter of less than 2mm, 15 percent of construction waste with the grain size of less than 8mm and the power content of less than 10 percent, and 20 percent of cement; moreover, a water reducing agent, a water repellent and an accelerating agent are added into the materials, and water of which the weight accounts for the total weight of the slag, the fly ash, the construction waste and the cement dry material is between 17 and 22 percent is added into the mixture; and the production process comprises the following: crushing raw materials, screening, preparing materials, mixing and stirring the materials, extruding by a slat extruder, curing, cutting, lifting the slab and pile-curing. The light wall slab has the advantages of improving the construction speed of single buildings, saving energy, increasing usable floor areas, meeting building requirements on various levels and prompting the wall material to develop towards industrialization and modernization of the housing industry. The light wall slab can promote the development of internal wall slabs and external wall slabs, and increase types of heat preservation wall slabs. Compared with expanded perlite, the sound insulation property of the industrial residue light aggregate wall slab is improved by more than 30 percent.