The sap engineerings have important function in war; at the same time

it is ease to be struck by cannonballs. In order to increase the protection capability of the sap engineerings

the basic theories and energy dissipation of wave are used for analytical research on rock deformation

energy dissipation during the process of rock friction and the propagation characteristics of explosive stress wave which passes through the interface between rock and air. Based on six conditions of normal working environment

the numerical simulation results for the inspection nodes are simulated by finite element analysis software ANSYS—LS-DYNA . Comparisons with the theoretical analysis show that the unloading hole plays its role of reducing explosive loading. So that a new way for the protection design of sap engineerings is offered.