The extinguishing mechanism of silicon gel extinguisher is discussed.Its properties are studied,including heat stability,retenetive water character,resisting combustibility,heat chemistry nature and activation energy.Its extinguishing nature is observed by means of extinguishing experiments.The experiment results show that silicon gel has better fire-retardant and fire-extinguishing properties so that it can fully develop the cool-function of water and raise the fire-extinguishing velocityefficiency and security of water in fire-fighting.