Abstract: As an effective means of slope control and rock mass protection，presplitting blasting tech‐ nology has a wide range of engineering application prospects in open-pit mines. In order to clarify the influ‐ ence of line charge density and reinforcement parameters on the formation effect of pre-cracking，the physi‐ cal and mechanical parameters of different lithology are obtained through rock mechanics test，and the hole wall pressure and reasonable hole spacing range are deduced by theoretical calculation. On this basis，the explicit dynamic finite element simulation method is used to construct the presplitting blasting model respec‐ tively，and the failure mode and crack width evolution process of rock mass under different linear charge density and reinforcement setting conditions are compared and analyzed. The results show that the linear charge density is the key factor affecting the formation of pre-cracking. With the increase of density，the width of pre-cracking increases，and the function relationship can be obtained by fitting. The reinforcement has little effect on the change of crack width，but increasing the reinforcement properly can effectively pro‐ long the action time of detonation products and promote the formation of complete cracks in the uncharged section. The study result provides theoretical support and numerical basis for the optimization design of pre‐ splitting blasting parameters under complex geological conditions，and has important guiding significance for improving blasting control accuracy and ensuring slope stability.

Key words: presplitting blasting, linear charge density, residual height, pressure on bore wall