Computational prediction and design of sandwich structures have drawn a lot of attention because of their interesting bond characteristics and broad applications. Most studies focus on the thermodynamic stability. In this study, we performed a series of Born-Oppenheimer molecular dynamics (BO-MD) simulations to investigate the dynamic stability of the well-known sandwich structure CrB₂₄. The aim was to find at which temperature the sandwich structure is stable. The MD results showed that the sandwich structure has an extremely poor dynamic stability. Additionally, one highly symmetric endohedral structure with a chromium atom at the center of a B₂₄ cage was found. As a demonstration, we attempted to point out the importance of dynamics studies on the future design of sandwich structures.