In order to reduce the differential settlement between the new and old embankment, prevent the new embankment collapsing and the pavement destroying, pile-supported reinforced-earth wall is carried out to widen embankment on rheological soft-clay.The existing railway slope was cut to 1∶0.5 after opening to traffic at different times.Then filling subgrade and operating it three years.The software FLAC^3D was used to build a model to analyse how the operation time can affect the movement of retaining wall and the settlement of embankment and foundation after widening the subgrade.Discussing how the position of the pile and the way of widening will affect this subgrade widening structure.The experimental results demonstrate that the pile-supported reinforced-earth wall has great stability and bearing capacity.After widening, the existing roadbed appears reverse slope phenomenon obviously, but the slope ratio is less than 0.4% of the allowable road slope ratio of road functional requirements and structural requirements.Using pile-supported reinforced-earth wall can not only reduce the influence of widening subgrade on existing subgrade, but also reduce the settlement of the widening subgrade.