In order to research the reusability of the high speed flight vehicle in the future, according to the practical application environment of the silica aerogel composites, the silica aerogel composites were treated single-side heat treatment at 400 ℃ for 1800 s, evaluating the stability of silica aerogel composites at 400 ℃ via the method of monitoring the quality loss ratio, size shrinkage ratio,, insulation properties, microstructure change .The results indicate that silica aerogel composites were exhibited excellent stability after single-side heat treatment 10 times, including the variations of mass loss, XYZ direction size shrinkage, thermal conductivity. The variation of elevated temperature and ambient temperature thermal conductivity and microstructure are very small. Comprehensively considering all properties of silica aerogel composites, it can reach up to 10 times.