Abstract: Silica aerogel is a nice thermal insulation material. It has excellent characte- (ristics) like nano-structure, high porosity(more than 95%), large surface area(about (1 120 m~(2)/g)), low density(0.003 g/cm~(3))and low thermal conductivity(0.023 W·m~(－1)·K~(－1)). Some new processes were studied to reduce the preparation cost of silica aerogels.Thermal conductivity was measured. The thermal transfer mechanics was analysed, and different kind of insulation materials were compared.