Taking the sand-soil tower foundation slope of Dingbian County in northern Shaanxi as the research object,the physical and mechanical properties of sand loess were studied by means of laboratory tests,and compared with the physical and mechanical properties of Xi'an sticky loess. On this basis,the finite element software MIDAS was used to simulate the stress-strain characteristics of the tower foundation slope under different working conditions,and the failure mechanism of the towe foundation slope in the sand loess area is revealed. The results show that the natural density and dry density of sand loess are lower,the pores are higher,the coarse silt content is more,the friction strength is obviously larger,and the cohesive force is smaller. The finite element simulation shows that with the increase of influencing factors,the tensile stress of the slope shoulder increases continuously,the shear stress of the slope foot is continuously concentrated,the stability of the slope is gradually reduced,and the potential sliding surface is finally formed and destroyed,wherein the wind load and rainfall is are major factors affecting slope stability and stress strain.