Abstract: A super-large pile group was adopted in the Li-Zigou large-span bridge, one of the major projects on the Nei-Kun railway. A physical model of the super-large pile group is constructed to gain a better understanding of its mechanical behavior by observing the distribution of internal forces and of its deformation behavior under horizontal load. The results show that the maximum bending moment shows up in the vicinage of the cross-connection of the pile and the bearing platform. The bending moment decreases linearly or nonlinearly with the load along the pile from top to bottom. The peak values of the bending moment and its variations differ depending on the combination of vertical and horizontal loads.