The propagation character of shock wave in SiO2 aerogel under explosive loading is studied using a polyvinylidene fluoride piezoelectric sensor. The propagation character of shock wave in aluminum foam is also determined for comparison. The results show that the peak stress of the shock wave follows the exponential attenuation relation with the propagation distance of the shock wave in SiO2 aerogel. The shock wave attenuates more obviously in SiO2 aerogel than in aluminum foam. The special nano-porous network structure of SiO2 aerogel results in better attenuation effect of shock wave in aerogel. The shock wave velocity in SiO2 aerogel is extremly low, thus the chase of the unloading wave leads to the further attenuation of shock wave.