As the existence of load-carrying plate DX pile changes the load transfer mechanism of piles, improves capacity and also significantly reduces the settlement deformation. In this paper, on the basis of field trials, the distribution characteristics of load of DX piles and equal diameter piles are analyzed, and thus according to Geddes solution the soil pile superimposed stress is solved by using a program developed by authors. The results show that in the same load conditions, the settlement of DX pile is 0.55 to 0.80 times as compared with equal diameter pile. The changes of the settlement caused by load-carrying plate are analyzed.