DX pile group is simulated by numerical analysis software FLAC3D to study the mechanics behavior and the pilesoil settlement rules. Analysis of the influence of pile spacing and plate arrangement to ultimate bearing capacity and settlement control, and comparison of the ultimate bearing capacity of straight pile group with 8 piles with the DX pile group with 6 piles are done. The result indicates that the pile of DX pile group has the same bearing mechanism with the DX single pile. The displacement of the soil below the bearing plate is greater than that above the bearing plate, which leads to the free surface of the upper cavity. 3D (D is the diameter of the bell) pile spacing can perform the best bearing capacity and settlement control. Within the same stratum, bell arrangement (staggered arrangement and parallel arrangement) has little effect to the bearing capacity of DX pile group. The ultimate bearing capacity of DX pile group with 6 piles is as 1.27 times as the straight pile group with 8 piles. With DX pile group, we can not only effectively control the settlement, but also reduce the number of piles and save the project cost. These research results provide valuable basis for the rational design of pile groups of this type.