Potassium silicate solution and styrene-acrylic emulsion were used as film-forming agents. The physicochemical and fireproof properties of the inorganic fire-retardantcoatings were improved by controlling the amount of pigment fillers and fire retardants. Andthe coating fire protection mechanism was analyzed by TG-DTG，XRD and FT-IR. The results showed that the optimal process parameters for the preparation of potassium silicate inorganicfire-retardant coatings were 5% talc powder，4% titanium dioxide and 6% glass powder as pigment fillers，5% dolomite，20% aluminum hydroxide and 2% expandable graphite as fireretardants. The results of TG-DTG，XRD and FT-IR showed that the mass loss of coating was 36. 87% before and after fire protection and a new ceramic phase was formed. After 1 h of fireresistance of the coating，the maximum temperature of the back plate was 286℃，and the coating could be expanded about 9. 2 times after burning. The physicochemical and fireproofproperties of potassium silicate inorganic fire-retardant coatings were greatly improved.