A series of silicone rubber foam (SF)/silicon dioxide (SiO2) nanocomposites were prepared by room temperature vulcanization. The effects of SiO2 content on the crosslinking density, cell structure, physical and mechanical properties, thermal properties, dynamic thermomechanical properties of SF/SiO2 nanocomposites were studied. The results indicated that SF/SiO26 nanocomposite with 6.0 wt% SiO2 content had the optimal comprehensive performance. The cushioning properties of SF/SiO26 nanocomposites were investigated by the static compression test. The cushioning coefficient of SF/SiO26 nanocomposite was very close to expanded polyethylene (EPE). Moreover, the fatigue properties of SF/SiO26 nanocomposites were investigated by the dynamic compressive fatigue test. SF/SiO26 nanocomposite exhibited long fatigue life (6.0 million times) and high height retention rate (99.0%), which was far greater than those of EPE (0.29 million times, 54.5%). The cushioning coefficient of SF/SiO26 nanocomposite was almost no changed before and after fatigue test, which was obviously superior to traditional cushioning material EPE. Such SF/SiO2 nanocomposite with excellent fatigue buffering properties could be used as a cushioning material in the packaging field.