Abstract: The study on the deformation and failure mechanism of loess slope is of great significance for the prevention and control of loess landslides. Slope with loess-mudstone interface is one of the loess landslides types. Researchers have clearly understood its basic failure process and mechanism. However, its deformation and failure process under different rainfall patterns, especially under heavy rainfall conditions, need to be further studied. Therefore, this paper conducts a laboratory rainfall experiment of the loess-mudstone interface slope model and studies its deformation and failure mode under heavy rainfall conditions. It designs two kinds of rainfall patterns. They are the continuous strong rainfall and the intermittent strong rainfall. It compares and analyzes the infiltration characteristics and failure modes. The results show that the rainfall infiltration rate gradually decreases from the leading edge to the trailing edge of the slope under two rainfall conditions. In the surface of the slope, the infiltration rate gradually increases with the intermittent to continuous transition of rainfall. In the deep parts of the slope, the slope structure affects the infiltration rate. The slope under intermittent rainfall appears as sliding and fracturing instability, while in the continuous rainfall condition, it behaves as creeping and fracturing failure.