Abstract: To investigate the vertical bearing characteristics of bridge pile foundations in the steep slope karst development area, centrifugal model tests were conducted to investigate the effect of vertical loadings on the payload-settlement curve, on the ultimate bearing capacity, on the pile axial force and, on the pile side resistance when the pile foundation crosses the karst cave and is in a steep slope section, so as to give the key parameters affecting the vertical bearing characteristics of the pile foundations. The results show that the vertical ultimate bearing capacity of pile foundations decreases with increasing slope. The influence of the ultimate bearing capacity increases 13.8% - 45.3% when the slope at 30° - 75° compared to horizontal foundation. Slopes greater than 60° have a significant effect on the vertical ultimate load carrying capacity. The pile shaft force decreases gradually from the top to the bottom of the pile, and the decay rate and reduction decrease with increasing slope; the decay rate of the shaft force is slower in the overburden, faster in the rock layer, and no decay in the cave. The pile side resistance is significantly greater in the bearing layer than those in the upper rock and in the soil layer, and is zero in the cave. The pile side resistance decreases with increasing slope at the same depth, and the reduction rate increases with increasing slope, and the reduction rate in the powder clay layer is smaller than that in the moderately weathered greywacke layer. As the slope increases, the proportion of pile end resistance in the vertical bearing capacity of the pile foundation gradually increases, and the proportion of pile side resistance gradually decreases. For the slope less than 60°, the proportion of pile end resistance is less than 20%. As the slope greater than 60°, there is a significant turnaround in the proportion of both, with a shift in the type of pile foundations changes from friction piles to end bearing piles.