Abstract: In view of the characteristics of low coal hardness and permeability of a certain area, in order to confirm suitable cartridge radius and non-coupling charging coefficient, and improve coal blasting efficiency in the area, software of ANSYS/LS_DYNA was used for simulation analysis of blast cracking, and radius of compression zone and the maximum crack length under different cartridge radius and non-coupling charging coefficient were obtained. The analysis results show that the most suitable cartridge radius is 30 mm, and the non-coupling charging coefficient is 1.5 when the coal is on the pre-splitting blasting anti-reflection; in a certain range, blast cracking effect of high hardness coal is better than low hardness coal, the main performance is that for the high hardness coal, coal crushing area radius is relatively small and cracks number is more than low hardness coal, while the crack length is also large.