Studying the blasting effect with different coupling coefficient of blast hole can meet the needs of high-efficient rock-breaking in existing coal mine roadway driving.By exploring the extent of the rock's explosive and fracture zone,the blasting effect is simulated under the hole diameter of 32 mm,35 mm,42 mm with the explosive cartridge diameter of respectively 27 mm,29 mm,35 mm and 42 mm using the nonlinear dynamic simulation software.Meanwhile,the blasting process of charge with different coupling coefficients and the effective stress peaks at different positions away from the hole center are obtained.The effective stress peaks and subsequent stress changes of rock at different time points are visualized,and the peak stresses at the same point under various conditions are compared.The results show that the stress peak decreases rapidly with the increase of the distance from the hole center,and the attenuation degree of the peak effective stress peak of the coupled charge is smaller than that of the uncoupled charge at both near and far.The effective stress of rock mass around coupled charge is much larger than that of uncoupled charge,and the peak value of effective stress increases with the diameter of borehole.The effective stress peak attenuation of coupled charge is slower than that of uncoupled charge.The uncoupling coefficient has a greater effect on the effective stress peak than the explosive diameter.And through the obtained radius of crack circle,the power of unit explosive is quantitatively calculated and compared,and the simulated power of unit explosive is 447.02 mm2 when 42 mm hole coupling charge is adopted,which is more suitable for the construction site.