Abstract: The cemented sand-gravel (CSG) dam is a new type of dam. At present, the academic circles have mainly carried out the researches on its structural form, stress distribution, and structural strength, but there are few related studies on the influences of the foundation on the CSG dam. In this study, through the design of geomechanical model tests the general operation of the CSG dam and the failure state on the complex foundation are simulated. Specifically, the typical dam section of Shoukoubao Dam and the dam foundation of No. 18 dam site area of Wudu Reservoir are selected for geomechanical model tests. Using the overload method, the model is tested for damage, and the deep anti-sliding stability of the CSG dam under this working condition is studied. The results show that the overload safety K_p of the model is 6.0, and the CSG dam has good adaptability to complex foundations. The main reason for the failure of the model is the failure of the structural surface of the dam foundation to form a slip channel, and finally, the dam body slips and loses stability along the slip channel. The research results may provide certain technical support and reference for the practical application of CSG dams on complex foundations.