Abstract: The constitutive model was described based on the theory formwork of elastic-plastic hydrodynamics for saturated soil under the explosive loading, including the relation of pressure and volumetric strain and the relation of pressure and failure surface. The explosion wave propagation and the interaction between media and structure were simulated numerically by using LS-dyna software, the results of numerical simulation is in close agreement with that of foregone experimental investigation. The reappearance of some special phenomena for saturated soil makes clear that the constitutive model is usable.