In order to study the combustion and physicochemical properties of fireproof sealant in different fire scenarios, according to the standard, power and hydrocarbon fire that may occur in UHV DC converter stations, the effects of three fire heating modes on the combustion process of fireproof sealant were studied. Changes of physicochemical properties at different time after combustion were studied too. The mass loss was paid attention to during the combustion process. The corrosion resistance, water resistance, acid resistance, alkali resistance, oil resistance, humidity and heat resistance and freeze cycle resistance were focused more among all physicochemical properties. Then the effects of three fire heating modes on fireproof sealant were compared. The results show that the early danger of power and hydrocarbon fire is much higher than that of standard fire. After 120 minutes of combustion, the total mass loss rate of fireproof sealant under the three heating modes is basically the same, reaching 85% . After the fire, the water resistance and acid resistance are seriously damaged. Electric fire and hydrocarbon fire have a greater impact on the damp heat resistance and freeze- thaw cycle resistance of fireproof sealant than standard fire.

fireproof sealant, fire heating mode, physicochemical properties, mass loss