Abstract: The present invention relates to an alkali metal silicate coating formed from alkali metal silicate represented by the chemical formula M2O.nSiO2 and lithium silicate represented by the chemical formula Li2O.mSiO2, wherein M is selected from sodium, potassium, or a mixture thereof, n is from 2.9 to 3.7, m is from 4.2 to 4.8, and the molar ratio of M2O.nSiO2 to Li2O.mSiO2 is from 2.2 to 4.8; wherein the alkali metal silicate coating has a thickness of from 630 to 1,450 mg/m2, preferably from 700 to 1,400 mg/m2, in terms of SiO2 as measured by fluorescent X-ray spectrometry. The present invention further relates to a preparation method of the coating. The coating of the present invention has excellent heat resistance, hot water resistance and stain resistance, as well as excellent damage resistance.