Abstract: In order to study the effect of confining pressure on damage evolution and energy dissipation of the failure process of concrete under impact, the SHPB experiments of concrete under different impact velocities and different level of confining pressures were simulated based on ANSYS/LS-DYNA finite element software. The results show that the peak stress increases linearly with the increase of confining pressure at different impact velocities, which can reach 3~4 times of the static compressive strength of concrete. Under the condition of confining pressure, the failure mode of concrete is compression-shear failure, and the average damage degree of the specimen decreases nonlinearly with the increase of confining pressure. Compared with the impact velocity, the influence of confining pressure on the damage degree is weaker. With the increase of confining pressure, the transmission capacity of the concrete is enhanced, and the reflected energy decreases nonlinearly, while the transmitted energy increases linearly. The energy dissipation of the concrete decreases linearly with the increasing of the confining pressure. On the other hand, the change trend of the reflection coefficients, transmission coefficients and the energy consumption of the specimen are consistent under different incident energy. When the incident energy is constant, damage degree of specimen decreases with the increasing of confining pressure, meanwhile, the variation range decreases as well.