The pile foundation of steel trestle bridges with inclined section and shallow overburden simultaneously bear the vertical load transmitted from the superstructure and the horizontal load caused by the impact of flowing water. The structural stress is more complicated than that of the flat ground pile foundation. Combining with an engineering example, the influence of vertical load on pile top displacement and pile body stress is analyzed, and the variation law of stress and pile body bending moment of steel-concrete composite piles is studied through the comparison of field static load test and numerical simulation. The results show that the vertical displacement of the column top is about twice that of the horizontal displacement under the action of vertical load and horizontal flowing water load, and when the vertical load exceeds 300kN, the vertical displacement of the pile top increases significantly. The bending moment of the pile body presents an S-shaped distribution, with a large negative bending moment on the upper part of the pile, and a more obvious impact on the rear pile. The external steel tube, the internal concrete and the embedded I-beam are jointly stressed with excellent load transfer performance. Stress concentration of I-beam occurs at the junction of the steel-concrete section and the embedded section. The research has referential value for the pile foundation of similar engineering projects.