Aiming at the influences of explosive enlargement and explosive lining on the density of surrounding media, numerical simulations and field tests are carried out. The results of numerical simulations by Dyna-2D are consistent with the conclusions of related studies in recent 20 years. The numerical simulations show that there exists a low-density zone at the inwall of explosively formed cavity or lining, and the density in the zone is lower than its initial one. But the field tests results do not support the above conclusions. Ten field explosive tests are carried out to confirm the density of the media. The results indicate that the densities of the cavity’s surrounding media, formed through either explosive enlargement or explosive lining, are all higher than their initial ones, and no so-called low-density zone exists. The following viewpoints are all mistaken that the density isn’t the highest at the inwall near the cavity, and that there exists a medium zone whose density is lower than its initial one.