Based on ANSYS/LS-DYNA,we carry out the numerical simulation analysis of underwater drilling blasting,establish the axial uncoupling and air axial uncoupled single hole drilling blasting model of water medium,and research the mechanism of rock blasting fracture.Furthermore,the superiority of the uncoupled charge structure of the water medium compared with the air uncoupled charge structure blasting is demonstrated by the numerical simulation,the energy utilization rate is greatly improved,and the optimal structural form of underwater drilling and blasting charge in the uncoupling state of the water medium is obtained.The structural form has certain reference value for the application of underwater reef engineering in waterway rectification and port terminal construction.