Abstract: The vacuum preloading technology for reinforcing soft soil foundation often uses the coarse sand as the horizontal drainage channel. For laying geotextile composite cushion in the new dredger fill soft soil ground, key construction techniques such as horizontal drainage systems, artificial surface crust layer and light board equipment are achieved. By monitoring pore water pressure and surface subsidence, during improvement , the deformation law of foundation soil is grasped. The test data of bearing capacities of foundation and soil before and after improvement show that the water content, void ratio of reclaimed soil decrease obviously after improvement, and the bearing capacity of foundation is up to 80 kPa. The test data indicate that the geotextiles in composite cushion can effectively replace traditional coarse sand cushion. It may provide reference for soft ground improvement of subsequent large-area foundation.