The displacement method of geotubes is widely applied to improving soft soil with a high water content and low bearing capacity in reclamation dam and road constructions due to its easy construction technology and significant treatment effect. When the weight of the geotubes is equal to the bearing capacity of foundation soil, the soil attains limiting equilibrium condition. It is necessary to estimate the relationship between the penetration depth and height of the geotubes. In this paper, model tests of three widths of geotubes are carried out, and the relationships between penetration depth and height, the displacement and upheavals of soil are revealed. In order to simulate the process of penetration of three geotubes, the Coupled Eulerian-Lagrangian approach(CEL) in ABAQUS software is used to simulates the process of penetration of geotubes. In this simulation, the geotube and silt are described as Lagrangian body and Eulerian body, respectively. The relationships of penetration depth with height of the geotube as well as displacement of the silt are obtained. The accuracy of the simulation approach is verified by model test results and theoretical result, showing that the coupled Eulerian-Lagrangian approach can be applied to predicting the penetration of geotubes very well.