Dynamic response of a deposit slope under seismic excitations are very complex, and it is insufficient to evaluate the seismic stability of slope just by using the single seismic safety factor. Through the large-scale shaking table tests, the influences of the input seismic wave are investigated on the permanent displacements of slope surface under multiple sequential ground motions, and the failure mechanisms of deposit slope are analysed. The experimental results show that the vibration type of seismic wave can result in more permanent displacement than the impact type of one at the same peak acceleration. It is also found that the predominant frequency of seismic wave has significant effect on permanent displacement. When the peak acceleration of seismic wave reaches 0.2g, the large gravel particles on the deposit slope surface begin to roll. The corresponding permanent displacement of slope surface begins to accrue, and it increases significantly when the peak acceleration increases from 0.2g to 0.3g. An improved Newmark approach is used to estimate the permanent displacement of the crest, with assuming that the formulation of the yield acceleration is geomertric-dependent. It is shown that the permanent displacements of slope surface can be used to evaluate the deposit slope dynamic stability.