With the development of high-speed spacecrafts, the properties and heat transfer simulation of thermal protection materials used by the spacecrafts are of great significance. This study aims to study the properties of silica aerogel composites and heat transfer simulation. The results indicate that thermal conductivity of the silica aerogel composites is only 0.018W/m?K and transient heat transfer simulation shows good agreement with the experimental data. Thus the simulation method can forecast the experimental conclusions and optimize the geometric structure of the composites.