Abstarct: Abstract Using explosive method for drilling in hard rock in mining and construction projects is one of the most flexible drilling methods which can be a quick, low cost and practical method depending on the area of operation. In this study, using a numerical method, the explosion is simulated in a high-speed explosive block. Most materials in fast loading exhibit very different behavior than slow loading. Phenomena that occur during high-speed dynamic processes are usually hard to detect and record in experimental experiments. Therefore, numerical methods are useful in these studies. In the present study, using LS-DAYNA software, first considering the RHT behavioral model and Lagrangian method for rock and High Explosive Burn behavioral model and particle hydrodynamic method for explosive modeling of crack propagation and fracture propagation in blast rock The explosives have been discussed and the results have been compared with the experimental and numerical results. The results show that the simulated model has results similar to real and acceptable conditions. Then, for the explosive block with one and two blast holes, we examined different heights for the two explosives. The results show a relationship between the length of the explosive and the rate of crack.