The xerogel and aerogel RDX/SiO₂ nanocomposite energetic materials were prepared using sol-gel method. TEM and XRD were used to analyze the surface topography and the crystal structure. The thermal decomposition and the impact sensitivity for RDX/SiO₂ nanocomposites were also tested. The results show that compared with pure RDX,the DSC decomposition peak temperature of the aerogel RDX/SiO₂ containing 45% RDX decreases by 15.4 ℃. The xerogel framework can effectively desensitize RDX,and the impact sensitivity descreases greatly with the increase of the SiO₂ framework content.