Abstract: Due to high water sensitivity of dispersed soil, the dispersed soil slope is prone to deformation and failure. At present, there is a lack of overall understanding of the failure characteristics and prediction of the dispersed soil slope. In this paper, six groups of model tests are designed based on fractal theory. The failure mode of dispersed soil slope is studied by close-range photogrammetry technology, and a failure time prediction model of rainfall-induced dispersed soil slope is proposed. The test results show that when the fractal dimension value is large (2.7687~2.8234), the progressive hydraulic erosion failure is dominant. When the fractal dimension value is small (2.4977~2.6879), it is dominated by sliding failure. When the fractal dimension value is moderate (2.6879~2.7687), it is dominated by shallow surface sliding failure, which has the common characteristics of erosion and landslides. The instability characteristics of dispersed soil slope are divided into three stages: seepage and dispersed disintegration (initial erosion), fluid-solid coexistence (constant velocity erosion) and near-saturated slide (accelerated erosion). In this paper, the slope model is used and SRR is selected as the prediction index. The prediction area is determined by improving the tangent angle model, which can predict the failure time of progressive-sliding type landslides induced by rainfall. In this paper, it is found that the mean Root Mean Square Error (RMSE) of the prediction results of the failure time of the landslide is 7.68, and the mean Relative Error (RE) is 2.4%. The research results are of great significance for understanding the failure characteristics of dispersed soil slopes, and provide a new model for accurate prediction of rainfall-induced dispersed soil landslides.