The invention discloses an inorganic functional coating, the composition and parts by weight of which are as follows: 15-36 parts of white cement, 20-45 parts of ash calcium powder, 23-60 parts of heavy calcium powder, 8-16 parts of talcum powder, 5-16 parts of kaolin, 2-12 parts of metakaolin compound, 4-14 parts of diatomite compound, 3-12 parts of diatomite, 1-3.5 parts of fiber mixture, and 1-5.5 parts of auxiliary agent. Metakaolin compound includes metakaolin, mineral powder and negative oxygen ion powder, diatomaceous earth compound includes diatomaceous earth and tourmaline, fiber mixture includes lignin fiber and hypromellose, negative oxygen ion powder includes tourmaline , hexacyclic stone, rare earth oxides, monazite, microcrystalline mother powder any two or more. The invention can release negative oxygen ions, absorb and decompose formaldehyde and VOC, settle PM2.5, remove peculiar smell, purify air, and make the concentration of negative ions released in the room reach 1000ions / cm 3 Above, to achieve a very fresh air quality, to meet the environment required by the healthy life of the human body.