Abstract: The consolidation time in the centrifugal model tests is 1/<>n² of that in the prototype, thus the long-term settlement of deep soft clay ground can be simulated within short time. Based on the principles of centrifugal model tests, different test schemes are designed and centrifugal model tests are employed to study the improvement mechanism of D-M method. The tests results show that the D-M method is feasible to improve deep soft clay ground. Compared with the deep mixing, the D-M method is beneficial to reduce the differential settlement and the cost of ground treatment. At the same time, the method has better treatment effect than PVD in post-construction settlement and differential settlement.