Abstract: To study the dynamic damage characteristics of sandstone under different water bearing conditions, three different kinds of samples with different moisture states (dry, semi-saturated, and saturated) were prepared. The impact damage of the rock was tested using a split Hopkinson pressure bar (SHPB) with four values of low incident energy. The T₂ spectrum curves, porosity, and pore image of the samples were obtained by scanning the samples by nuclear magnetic resonance test. The results show the following:(1) an increase in the impact energy led to increased average strain rate and strength; (2) after impact, the porosity and porosity variation rate of every sample under different water bearing conditions increase with different amounts; (3) compared with the test before impact, T₂ spectrum curve has obvious right movement trend and large pore peaks increase. The greater the impact energy increase, more obvious the large pore peaks increased are; (4) nuclear magnetic resonance images show that the number and size of pores increase, which show the expansion and evolution of pores in the rocks.