Abstract: Frequent loess landslides in China's Loess Plateau are closely linked to the effects of dynamic water infiltration. To clarify the failure mechanism of the loess slope under the influence of seasonal sustained rainfall infiltration and the reverse seepage of confined water, a case study of the Hongya Village landslide was conducted. Based on the field investigation, the response characteristics and spatio-temporal distribution of soil physical and mechanical indexes of loess slope under the condition of rainfall infiltration and reverse seepage were studied by numerical simulation method. Moreover, by analyzing the landslide failure process, the slope stability and stress-strain conditions are understood, and the key roles of rainfall and confined water pressure in the loess landslide process are revealed. The results show that Neogene strata and loess-mudstone dual structure provide favorable geological conditions for landslide occurrence. Furthermore, the abundant hydrogeological environment and sufficient rainwater supply provide the necessary dynamic water infiltration conditions for the formation of landslide. Continuous rainfall is an important inducing factor of Hongya Village landslide, and the reverse seepage of confined water is the key inducing factor.