The invention relates to a foaming type inorganic heat insulation plate, a preparation method thereof and a heat insulation layer thereof, which belongs to the technical field of a heat insulation plate and a heat insulation layer, and provides a foaming type inorganic heat insulation plate with high efficiency and energy saving, a preparation method thereof and a heat insulation layer thereof. The heat insulation plate is prepared from the following raw materials in parts by weight: 10-55 parts of composite light weight admixture, 10-55 parts of cement, 5-30 parts of lime, 3-20 parts of plaster, 1-10 parts of wollastonite, 10-55 parts of water glass, 10-60 parts of foam body which is foamed by a foaming machine through a foaming agent, 3-20 parts of fly ash, 0.1-3 parts of gel powder, 0.05-2 parts of cellulose ether, 0.01-2 parts of glauber salt, 0.1-3 parts of water reducing agent, 0.1-2 parts of hydrophobic agent, 0.01-1 part of mekarlon, 1-10 parts of bone glue, 5-30 parts of emulsion, 4-12 parts of waste slag, 1-45 parts of water and 0.02-1 part of aluminum powder. The invention is applied to the technical field of heat insulation materials.