In order to decrease relative settlement，foundation treatment plays an extremely important role in bridgehead transition section，especially，the situation of building the bridge piles firstly，and then processing piles． On the basis of engineering practice，the authors analyzed the influence of foundation treatment on bridge piles in bridgehead transition section by finite-element method ( FEM) ． This research has positive significance in predicting displacement of bridge pile，directing construction of foundation treatment，and improving quality of engineering and so forth．