Discrete element method is applied to simulate the loose particle flowing in the process of high velocity compaction. Assuming that the powder is formed by viscoelastic metal particles, a constitutive model of viscoelastic powder in high velocity compaction described by force-displacement is deduced. The governing equation of particle flow for high velocity compaction is established. The calculation method of the contact force is improved. Based on computing software PFC for the discrete element method, the particle flow and density distribution during high velocity compaction is simulated. The simulation results are consistent with the experimental. The influence of damping coefficient variation on the convergence and divergence of solving process and the density distribution of green compact is analyzed