Abstract: Based on the characteristics of soil dynamic consolidation(DC),nonlinear FEM with momentary display function is applied to simulate the collision process of dynamic consolidation.This study simulated the dynamic consolidation of loess numerically to generate an elastic-plastic finite element representation of soils.In this study,material nonlinearity,geometric nonlinearity,contact nonlinearity,movement nonlinearity and coupling characteristics of them were taken into account.The histories of soil stress,collision force of hammer were obtained;at the same time,the deformation of soil and soil density were acquired at different depth,and comparisons were made of the displacement and the stress of soil.The consolidation mechanism of dynamic compaction is investigated and some useful conclusions are gained.