The effect of silica aerogel (SiO₂) on the mechanical and bonding strength and ablativity of room temperature vulcanized (RTV) silicone rubber used for inhibiting of solid rocket propellants were investigated. The results show that SiO₂ is an effective reinforce filler. With the increase of SiO₂ content, the tensile strength of silicone rubber and the bonding strength of silicone rubber coated HMX-CMDB propellant or Al-RDX-CMDB propellant increase, but the ablation resistance of silicone rubber becreases.