Abstract: The establishment of finite element equation and the numerical analysis in dynamic compaction of soil are discussed. The numerical solution of dynamic compaction in the site of Shanxi Fertilizer Factory is given. The stress-field, deformation-field, acceleration-field, density-field of the foundation soil during and after dynamic consolidation (DC) are investigated and compared with practical figures. The calculation results are close to the test data. A new model is proposed and adopted to analyze the vibration characteristics of soil after DC. Two practical projects are studied and the results are compared with those of elastic model and ideal elastoplastic model. The model is shown to have great advantage in the analysis of the vibration characteristics of soil after DC.