Abstract: The paper investigated the effect of pre-stress on thespalling of materials. Based on the deformation characteristic of sphericalspallation, pre-strain in the radial direction of LY12 plane sample was madeby heat assembly within excess conjugation. The spalling response of thesamples were tested by VISAR with one-dimensional gas-gun impact experimentsin different pre-strain states. The experimental results show that thepullback amplitudes of the free surface velocity and the spallation strengthof the samples obviously decrease in the pre-stress state under the sameimpact velocity. Moreover, numerical simulations were performed with thedamage constitutive model. The numerical results indicate that thespallation strength of materials have a strong relationship with theexternal stress fields, and indirect with the structures.