Abstract: As a foundation treatment method, dynamic compaction replacement is mainly used to improve the bearing capacity of foundations and reduce settlement, but the research on its use as a foundation pit support has rarely been reported.In this study, the effects of different dynamic compaction replacing rates and slope rates of foundation pit slope on the slope stability of a foundation pit were discussed through a series of indoor model tests.Three FEM models of soil-pile whole simulation, soil pile separately simulation, soil pile coupling simulation were established to verify the results of indoor model test.The results showed that the horizontal displacement decreased in a decentralized manner in all directions, and the horizontal displacement change trend of indoor model test and numerical simulation was consistent and had a high degree of agreement.The stability coefficient of the slope increased with the increase of the displacing rate.The addition of interface units between piers and soil improved the interaction between piers and soils, which can effectively improve the accuracy of numerical simulation.