The embodiment of the invention discloses an infrared high-emissivity coating material which is prepared by mixing an infrared high-emissivity powder material and a colloid material, wherein the infrared high-emissivity powder material is prepared from iron-ore slag, iron oxide, manganese oxide, zirconium oxide, chromic oxide and silicon carbide through a treatment process of ball milling, mixing, high-temperature roasting and superfining; the colloid material is prepared by mixing water, sodium silicate, carboxymethyl cellulose and superfine silicon dioxide according to a certain weight ratio. The coating material has the advantages of high infrared emitting ability, stability, difficulty in aging, high binding ability of the coating with a substrate, long service life, low price and the like.