The invention discloses a nano ceramic coating capable of being cured at a normal temperature. The nano ceramic coating comprises a component A consisting of silicon sol, pigments, filler and water, and a component B consisting of siloxane, an aid, a drier and a solvent. The nano ceramic coating can be cured at the normal temperature, so that the application range is enlarged. In addition, the invention also discloses a preparation method of the nano ceramic coating capable of being cured at the normal temperature. The preparation method comprises the following steps: step 1, weighing the silicon sol, pigments, filler and water according to a corresponding ratio, mixing, stirring an obtained mixture, grinding the uniformly stirred mixture to powder with fineness of not higher than 25 micrometers, and adopting the powder as the component A; weighing the siloxane, aid, drier and solvent according to a corresponding ratio, mixing, uniformly stirring an obtained mixture, and adopting the mixture as the component B; and step 3, sufficiently mixing the component A and the component B according to a ratio, and generating the nano ceramic coating.