Abstract: The construction of city-connected high-speed railway in Northeast China has confronted a difficult problem in improving the bearing capacity of soft soils. The construction interval is in a small basin. The thickness of the silty clay is from 0.4 m to 9.6 m. There exists irregular size of erratic stones, the diameter of the stone is from 0.2 m to 2 m. The volume fraction of the stone is around 15%～20%. The drilling tool is prone to be broken when the bit meets silty clay, and the pile hole is easy to be inclined. It is technically poor and the economic feasibility is low. This problem is solved by applying the dynamic compaction replacement technology in reinforcing the stone subgrade of high-speed railway. By using the improved technology, a steady subgrade and economic benefits are achieved.