As a kind of destructive geological disaster, earthquake and rainfall are two key factors to induce landslide. From the perspective of earthquakes occurred during rainfall, this paper improved the Newmark model based on the Green-Ampt rainfall infiltration model, and derived the slope safety factor FS under the coupled action of two factors. The seismic landslide risk prediction and the influence of slope and infiltration depth factor on the displacement in an area of Ludian County, Yunnan Province were carried out under three conditions, i.e., no rainfall, rainfall with ponding, and rainfall without ponding. Then the Newmark cumulative displacement distribution and risk zoning in the study area were obtained through a comparison between the three cases. The results show that: compared with the case without rainfall, the area proportions of high-risk area of earthquake landslide in the latter two cases increase from 1% to 9% and 12% with the increase of rainfall time, respectively, and the area proportions of low-risk landslides reduce from 51% to 35% and 33%, respectively. With the increase of slope and infiltration depth, the displacement and the risk of landslide also increase. The improved Newmark model fully considers the promotion effect of rainfall on the occurrence of earthquake landslide and can better reflect the relative landslide risk of each site in the study area, thus having certain guiding significance for the landslide risk prediction.