Abstract: The difficulty of gravel soil landslide prevention and control is the accurate determination of its slip surface. Taking the thick gravel soil landslide on the left side of K14+030—K14+130 section of Dayangyun Expressway as an example, the authors fully identified the characteristics of the geological structure within the scope of the landslide and the mechanism of landslide genesis, on the basis of ground investigation, drilling, in-situ test, indoor test and stability analysis. The most important factor affecting the stability of gravel soil landslide is earthquake. The slip surface in the gravel soil layer was comprehensively investigated. The color of the slope is brown yellow, the graved is mainly in small particle size, and the density is loose. The drilling core has obvious scratches, and the gravel particles have a directional arrangement trend. The prevention and control strategy of double-row anti-slip piles + anchor cable frame lattice beam slope protection + interceptor ditch was finally proposed after selection, and this strategy achieved good management effect. The results of this study could provide some reference for the determination of the slip surface of similar thick gravel soil landslides and the study of prevention and control strategy.