The dynamic processes of NdYAG pulse laser ablation fused silica on the rear surface and inside are investigated by ultrafast time-resolved optical diagnosis. The evolution processes of time-resolved optical images of plasmas expansion and shock wave propagations are obtained. The results show that the multi-shock waves are emerged when the focused laser irradiates the rear surface of sample. Moreover, the reflection waves will be yielded when the generated shock wave arrives at the front surface of sample. Plasma channel is gained and the intense micro-explored damage sites will come into being when the laser focuses inside the sample. Meanwhile, it is found that the intensity of reflection and reflection shear waves at interface are determined by the incident angle of shock wave. The propagation velocities are different for different shock waves.