A light heat-preservation sound-insulation and supporting-free floor slab is characterized in that the light heat-preservation sound-insulation and supporting-free floor slab is composed of edge fixing steel angles, a sheet steel mesh, a connecting piece, a countersunk bolt, a cement fibrolite plate and light foamed concrete, the edge fixing steel angles are connected together to form a frame, the sheet steel mesh is arranged in the frame and is fixed, the lower face of the sheet steel mesh is connected to the cement fibrolite plate by using the countersunk bolt through the connecting piece, and the light foamed concrete is poured in the sheet steel mesh. According to the light heat-preservation sound-insulation and supporting-free floor slab, the precast sheet steel mesh and the steel angle frame fixed on the periphery of the precast sheet steel mesh bear loads mutually, the cement fibrolite plate is fixed to the sheet steel mesh, the light foamed concrete is poured in the sheet steel mesh, and therefore the light heat-preservation sound-insulation and supporting-free floor slab has the advantages of being light, heat preservative and soundproof. Due to the fact that the cement fibrolite plate is fixed below the sheet steel mesh and the frame as a soffit formwork, the purpose of being free of supporting can be achieved, the soffit formwork can be left without being dismounted and directly severs as decoration below, and plastering of the bottom face of the floor slab can be omitted. The light heat-preservation sound-insulation and supporting-free floor slab can be put into factory-like production, the inconvenience of site construction is omitted, time and labor are saved, and cost is low.