The organic-inorganic hybrid resin was prepared by sol-gel method as film forming resin of fire resistant coating,using pentaerythritol(PER)as carbon source,ammonium polyphosphate(APP)as acid source,melamine(MEL)as foaming agent,adding zinc borate,magnesium hydroxide,hollow glass beads as flame retardant and heat insulation filler,and adding auxiliaries,organic-inorganic fire resistant coatings were prepared.When the coating thickness is less than 3 mm,it has a good fire resistance limit.The effect of the amount of organic^and inorganic components in the organic-inorganic hybrid resin on the performance of the resin was studied.The amount of flame retardant filler and thermal insulation f iller was optimized and selected.The adhesion,weight loss,fire resistance limit and salt spray resistance of the fire resistant coating were tested.