Silicon-dioxide aerogel heat insulation composite material and preparation method thereof

The invention provides a fiber-reinforced silicon-dioxide aerogel heat insulation composite material and a preparation method thereof. According to the preparation method, mineral fibers with high mechanical strength, low heat conductivity and good heat stability serve as a reinforcing phase, silicon alcoholate serves as a precursor, fiber-composite silicon-dioxide wet gel is prepared by adopting an acid-base two-step catalysis method, and the block-shaped fiber-reinforced silicon-dioxide aerogel heat insulation composite material is then obtained through aging, modification, solvent displacement and supercritical drying. The prepared aerogel heat insulation composite material has the advantages of excellent mechanical property, good heat-insulating property and higher heat resistance. The aerogel composite material has a three-dimensional porous network-like structure, the compatibility between fibers and an aerogel matrix is good, the interfacial bonding is firm, and no obvious interfaces exist; and accordi