Abstract: Based on the existing researches on the shear characteristics of the pile-rock interface, the conversion relationship between the interface geometric parameters and the material properties and the parameters of the cohesion model is established. The accuracy of the contact model is verified by comparing with the field tests and theoretical studies. Combined with the indoor model tests on double-inclined rock-socketed piles, the corresponding finite element numerical model is established. The load-displacement curve and bending moment law of pile foundation are compared and analyzed, and the reliability of the model is verified. Then the full-scale model for the double-inclined rock-socketed piles with different dip angles is established to analyze the horizontal bearing characteristics under different vertical fixed loads. The results show that the rock-socketed system is a bearing system with synergistic effects of multiple factors. There is an optimal vertical design load that makes the horizontal bearing capacity of the double-inclined rock-socketed piles be greatly improved for are subjected to multi-directional combined loads. However, too large vertical loads and too small dip angles will increase the risk of pile cap instability.