The invention belongs to the field of enclosure wall materials of buildings, and particularly relates to a graphene and nonferrous metal tailings-based foamed light wallboard and a preparation methodthereof. The graphene and nonferrous metal tailings-based foamed light wallboard comprises a main material and an auxiliary material. The main material comprises the following component in parts by weight: 70-90 parts of nonferrous metal tailings; and the auxiliary material comprises the following components in parts by weight: 0.5-8 part of graphene, 1-15 parts of vermiculite, 2-10 parts of aluminum fluoride, 3-8 parts of aluminum silicate fibers, 5-15 parts of montmorillonite, 1-10 parts of clay, 5-20 parts of a cosolvent, 0.1-5 parts of a foamer and 0.1-5 parts of a stabilizer. The foamed light wallboard provided by the invention has the characteristics of being light, high in strength, light, high in toughness, fireproof, high-temperature-resistant, waterproof, anti-seepage, green, environmentally-friendly and the like.