Xonotlite compound super insulating material and preparation method thereof

The invention relates to an xonotlite compound super insulating material and a preparation method thereof. The xonotlite compound super insulating material comprises the following mixed raw materialsby weight percentage: 40 to 80 percent of SiO2 aerogel, 5 to 40 percent of infrared opacifier and 0 to 25 percent of reinforcing fiber. The preparation method comprises the following steps: adopting secondary particles which are provided with surface loose structures and are formed by mutual winding of xonotlite fiber with ultrafine diameters and SiO2 aerogel precursor prepared by adopting industrial water glass as silicon source to carry out compounding in advance; filling the SiO2 aerogel precursor in loose accumulation body of secondary particles of vacuum-dehydrated xonotlite, and drying after gelatinization and surface modification; filling the aerogel at the inner parts and the shells of the secondary particles of the xonotlite to form xonotlite-aerogel compound powder; and then mixing the xonotlite-aerogel