A mesh-free numerical model based on the Radial Basis Function Differential Quadrature is introduced to simulate the hydrodynamic response of the dam-reservoir-foundation system affected by earthquake acceleration. The governing equation of the hydrodynamic pressure of dam–reservoir system with non-vertical face shape was discretized using the presented model. Different formulation were implemented to model far-end of unbounded domain as boundary condition. For this purpose, the effects of fluid compressibility and energy depreciation in the reservoir boundaries were considered simultaneously. The presented model was used to determining the distribution of hydrodynamic pressure on dam face caused by earthquake acceleration in several practical examples and the obtained results were compared with available well-known analytical solutions. The comparison indicate that the accuracy and efficiency of the presented model are quite satisfactory.