The type, proportion and charging method of explosives will produce different stress waveforms, which have great influence on the rock crack propagation. Due to the complex interaction law between waveform parameters such as peak value, wavelength, energy and rise or fall rate, and the limited physical and mechanical test conditions, it is difficult to control waveform parameters quantitatively in blasting test. Numerical simulation has advantages in revealing the influence law of stress wave. In this paper, RFPA3D dynamic analysis software was used to simulate the crack propagation process of rock with a prefabricated crack under impact loads, and the effects of stress wave peak value, energy, rise rate and fall rate of stress wave on the rock crack propagation process are explored. The research shows that the rock crack propagation pattern under dynamic loads was affected by the rise rate of stress wave. The faster the stress wave rose rate, the more the broken around the hole was. For the crack propagation length, as the stress wave energy was increased, the crack grew longer. When the stress wave energy was the same, with the rise rate reducing, the crack grew farther but the broken degree around the hole was decreased. The rise rate and the energy of rise edge of stress wave affected the radius of comminution zone. The numerical simulation results well revealed the rock crushing mechanism of different stress wave peak value, energy and rise or fall rate. In practical engineering blasting operation, it is suggested to extend the action time by using water cannon mud seal or air column interval charge structure to expand the impact range of blasting. In addition, the appropriate type and proportion of explosives are also selected to increase the stress wave rise rate to improve the effect of hole edge crushing.