SiO₂ aerogel/foam cement composites were prepared by the vacuum impregnation method. Subsequently, the composition of pore structures, microstructure, hydrophobicity, density, mechanical properties and thermal conductivity of the composites have been systematically studied by SEM, FTIR and contact angle measuring instrument. The results show that SiO₂ aerogels were gelled and dried in the surface pores of the foam cement, finally fill with foam cement pores in the form of particles; according to the FTIR curve, there is no significant change in the groups of aerogels after the aerogels were gelled and dried on the alkaline surface of foam cement; the hydrophobic angle on the surface of modified foam cement is 141°; the density of the foam cement after impregnation is 309.4kg/m³, the compressive strength is 0.56MPa, and the coefficient of thermal conductivity is 0.046W/(m·K).