A detailed GEANT4 Monte Carlo study was performed to calculate the dose rate distributions of an industrial 60Co γ-rays irradiation facility, so it could provide a better service for the research of radiation hardening. All data produced during simulations were on-line stored and off-line analyzed by ROOT. With careful design of simulation processes, the relative errors were less than 5%. For the validation purpose, experiments with ferrous sulfate dosimeter were carried out. Furthermore, a computational model was constructed as a comparison. The relative deviations between simulated and experimental results were less than 5%. The satisfactory agreement of simulations between model and measurements indicates that our work has designed the processes of simulation and got the dose rate distributions in a correct way.Cited