We investigate the dynamic processes of the Nd:YAG pulse laser ablation of fused silica by ultrafast time-resolved optical diagnosis with a nanosecond time resolution. The evolution process of plasma expansion in air and shock waves propagation in the bulk are both obtained with spatial and temporal resolutions. Laser-induced damage in the bulk of fused silica with filaments and shock waves are observed. Thermoelastic wave, mechanical wave, and shock wave dependence on the laser fluence and intensity of the plasma are analyzed. The shock pressure P and temperature T calculated through the measured shock velocity D and the Hugoniot data of fused silica are measured.