Based on the engineering examples, the detailed calculation and analysis on the role offoundation deformation with large-scale preloading were carried out and compared with the deforma-tion of composite foundation treatment.The results showed that the influence depth of foundation de-formation under the large-scale preloading was large, and exceed the influence depth of conventionalload depth;compared with the composite foundation, the deformation of foundation under large-scale preloading was 25 times more than composite foundation;the negative skin friction should beconsidered in influence depth range under large-scale preloading.