Considering the variation of ground vertical permeability coefficient, the ground plane of sand equivalent permeability coefficient calculation method was presented. The field monitoring data were compared by using the Plaxis2D software. The variation form of settlement of soft base under the transition section of different soft foundation treatment were analyzed. At the same height of embankment the order of differential settlement after different treatment modalities in different transition section is as follow: sand compaction pile treatment, o rdinary sand processing and plastic drainage board, incrensingly. The results show that the transition section of soft foundation treatment scheme satisfies to the controlling criterion of differential settlements in Vietnam.