Abstract: The impact roller (IR) compaction method is an efficient and cost-effective compaction technique, which has been widely used in highway and airport engineering for subgrade compaction and ground improvement of soft foundation. The simulation tests are carried out based on the self-developed impact roller simulation device. The general displacement distribution characteristics of sand as well as the displacement distribution characteristics of sand at both sides of impact center and displacement variation characteristics of sand with impact time are studied. The results show that: (1) The shape of displacement distribution of sand in the impacting area appears to be semi-elliptical, and the displacement distribution range of sand is 2.5 times the distribution range of sand in the rolling area; (2) The displacement distribution of sand subjected to IR compaction is not symmetrical around the impact center; (3) The vertical displacement of sand increases with the increasing impact time, and the maximum displacement of sand appears at the left side of the impacting area.