Abstract: The bearing capacity of ram-compaction pile with composite bearing base is studied using FEM. The area of densified soil is determined by field sampling and model experiment. The model parameters of densified soil are determined by piecewise linear interpolation so that the special characteristics of bearing capacity of the pile can be accurately analyzed. The load-transferring mechanism, the optimum diameter of ram-compaction body and the difference of the vertical bearing capacity between rammed enlarged composite bearer piles and expanded head cast-in-place piles are discussed. The fundamental mechanism of bearing capacity of ram-compaction pile with composite base is enunciated. It is shown that the piles of this kind are superior in bearing capacity.