The utility model relates to a lightweight sheet for heat insulation and sound insulation, comprising a base plate with a hollow structure, wherein, the base plate comprises a keel frame; a plywood plate or a plastic plate is adhered on the two sides of the keel frame respectively; a composite silicate coating layer for heat insulation and sound insulation is covered on the surface of the plywood plate or the plastic plate. The utility model is characterized in that the lightweight sheet for heat insulation and sound insulation has the hollow structure; the cavity can be filled with heat insulation and sound insulation foam material; the surface is covered by the composite silicate coating layer for heat insulation and sound insulation. The utility model has the advantages of light weight, low thermal conductivity coefficient, significant heat preservation and heat insulation effect, good sound insulation effect, waterproof and moistureproof and convenient construction, and is an ideal heat preservation and insulation and sound insulation and absorption building material for the modern architectures.