Molecular dynamics simulations are used to investigate the shock-induced phase transformation of iron at a certain initial temperature, which shows that the temperature lowers the threshold pressure of shock-induced phase transformation. Also, the evolution of the loading and unloading waves is calculated and analyzed, and it is found that the velocity of the inverse phase transformation wave(during ε phase →α phase)equals the longitudinal sound speed of the wave front and is less than that of the wave rear. The pressure and density of unloading traces is also calculated, which affords a good explanation to the evolution of the unloading waves, and the phase transformation band of unloading is obtained, which shows the hysteresis in the reverse transformation.