The high energy dynamic compaction has been effective in a wide range of applications, effective reinforcement depth is an important indicator for evaluating the reinforcement effect and determining the dynamic consolidation plan. In this paper, taking a project of 10000kN·m high energy dynamic compaction for filled subgrade as a background, the finite difference software FLAC 3D was used to perform multiple dynamic compaction analysis. The stress after tamping was considered as a criterion to calculate the effective reinforcement depth. The results show that with the increase in the number of drops, the effective reinforcement depth first increases and then stabilizes. The growth rate of effective reinforcement depth after six drops is extremely small. The sensitivity ranking of soil parameters on the effective reinforcement depth is obtained by orthogonal test and extreme difference analysis. The drop distance and hammer weight are positively correlated with the effective reinforcement depth, while the hammer diameter is negatively correlated. The impact of hammer weight on the effective reinforcement depth is greater than the drop distance. The combination of heavy hammer and low drop distance has greater cumulative settlement and effective reinforcement depth under the same tamping energy. The formula for estimating the effective reinforcement depth of high energy dynamic compaction is proposed, and the uniformity of dimensions is achieved, which has a small deviation from the simulation results. It can provide reference for the same type of dynamic compaction project.