Abstract: Taking a gravity dam in southwest China as the research object, a three-dimensional finite element model which can reflect the dam body-foundation-reservoir hydrodynamic interaction and foundation slip surfaces was established by using nonlinear finite element analysis software ADINA. The influences of near-fault pulse type and non-pulse type ground motion on the anti-sliding stability of gravity dam were studied from three aspects of the distribution of foundation plastic zone, the state of contact surfaces and the slip of key points. The results show that the plastic zone of dam foundation, the range of the contact surfaces in the slipping and opening state and the post-earthquake displacement of key points of dam heel are larger than those of the non-pulse ground motion. The dam is more prone to instability under the action of pulse ground motion, and the influence of near-fault pulse ground motion on the dynamic stability of the dam cannot be ignored.