Fireproof gap sealing material is an environmentally friendly single-component fireproof sealing material that can quickly and effectively seal hard-to-reach gaps. It is suitable for joints between curtain walls and floor edges as well as gaps with high elongation. It boasts excellent airtightness and watertightness, superior elastic deformation capability, and will not crack upon use. In the event of a fire, it expands upon heating, quickly and effectively sealing the gaps left by the combustion of flammable materials. It prevents the spread of fire and smoke through the curtain wall, reducing the extent of fire damage.