Molecular dynamics simulation is applied to the investigation of energy exchanges between single hydrogen and graphite (001). In addition to energy transfer efficiency, in this paper we analyse various kinds of possible processes, which are the absorption on the upside graphite surface, reflection, absorption on the downside graphite surface and penetration, during the course of a hydrogen atom bombarding the crystalline graphite containing four graphene sheets. The simulation results show that the interlayer interaction has a big influence on the reflection, especially when the incident energy is larger than 20.0 eV. The reflection coefficient increases evidently compared with that in single graphene sheet case. If the incident hydrogen has a kinetic energy more than 25.0 eV, it can penetrate the four- sheet graphite at some striking locations. When the incident energy is larger than 28.0 eV, the energy transferring to the first graphene sheet is more than to the second graphene sheet. These results will be helpful for understanding the chemical erosion of carbon based materials and the tritium retention occurring in fusion devices.