We present a simulation method to reproduce the damage crater formation and particle ejection phenomena observed in the laser-induced surface damage process of potassium dihydrogen phosphate (KDP) crystals. Based on the smoothed particle hydrodynamics method, which is commonly used for solving shock and blast problems, equivalent explosion simulation models of the laser-induced damage process have been established. Moreover, laser damage experiments combined with time-resolved techniques are performed on KDP surfaces to investigate the impact of laser fluences on the shockwave propagation and the particle ejection speed. We find that the simulation models can predict the laser-induced damage behaviors of the KDP crystal, which verifies the validity of the proposed method.