Abstract: In order to study the energy transfer process at the interface of micro-channel charge and air gap, numerical simulation and experiments were implemented to achieve the pressure attenuated by the air gap. The commercial software AUTODYN was employed to simulate the non-ideal detonation process which was described by ignition and growth model. The peak pressures under different charge diameter, gap thickness and confinement material were obtained by numerical computation. Then, the obtained data was compared with that from measurement with Manganin piezo-resistance meter. The comparison result shows that the error is less than 10%, which verifies the numerical simulation would be a useful way to study the micro-channel charge problem. It is easy to see that the larger of the charge diameter or the thinner of the gap size the higher of the pressure. The 45^# steel is a much better confinement material than PMMA (polymethyl methacrylate) for air gap energy transfer.