Abstract: The dynamic stability of slope has always been the focus of geotechnical engineering and seismic engineering. In this paper, FLAC3D numerical calculation method is used to simulate the vibration velocity, displacement and stress of rocky slope under blasting action. And on the basis of comparing and verifying the peak value of blasting vibration, the dynamic response laws of rocky slope was analyzed. The results show that the seismic wave has a strong directionality and propagates mainly to the positive direction of the applied load. On the slope surface and at the foot of the slope, it is easy to produce the vibration strengthening field in a certain area due to the reflection of the force wave on the free surface of the slope. The maximum value of stress, whether tensile stress or compressive stress, appears near the slope foot. In the actual blasting excavation, the slope surface should be protected, especially the slope foot. The research results have certain reference for the construction design of rocky slope excavation.