Using the method of smooth particle hydrodynamics (SPH) to analyze the dynamic process of pulse jet breaking rock is an efficient way to avoid the problems of mesh distortion that occurred in traditional finite element method (FEM) in dealing with large deformation problems. The paper designs a numerical calculation model of the pulse jet breaking rock by introducing the J-H-C model and using the SPH method. The formation，propagation and attenuation of stress waves during the process of coal broken are simulated by use of this method. Through the analysis of stress wave changing law in time and space，the paper draw the stress wave pattern in the propagation process，and obtain the time characteristics and position characteristics of the propagation of stress waves during the process of pulse jet breaking coal rock. It is also found that the propagation characteristics of stress waves and the degrees of damage in different rock mediums are different. The calculation results are explained according to the analysis of the rock properties and wave propagation characteristics. The results of simulate process are identical with reality and had partly guiding significance to the engineering usage.