In order to study the deformation and failure of the slope under rainfall conditions, a typical slope model was established, and the seepage analysis was carried out through the finite element software Geostudio. The water content of the slope soil under different rainfall intensities was imported into the particle flow method. The weight and contact parameters of the particles are modified according to the position of the particles, and seepage force is applied to the seepage area. When the rainfall intensity is greater than the maximum infiltration capacity of the slope, the dragging effect of the slope runoff on the particles is added. The deformation of the slope and the failure process of the landslide under different rainfall intensities are analyzed. The results show that when rainfall occurs, the slope deformation is mainly caused by settlement, and the maximum deformation occurs at the top of the slope; When the rainfall intensity is large, the particles at the toe of the slope will slide due to the scouring effect, and the soil mass of the rear slope will be induced to produce a progressive traction landslide.