In order to reduce the interference of the adjacent EFP projectile of the combined MEFP warhead, the EPS foam with explosion-proof performance was selected, and the simulation and experimental study on the formation of EFP projectile with different density EPS foam was carried out by using the explicit dynamic analysis software LS-DYNA. The density of 0.02 g/cm³ 0.03 g/cm³、0.04 g/cm³ 0.05 g/cm³0.06 g/cm³ and 0.08 g/cm³ EPS foams were used as flameproof media to study the forming attitude and divergence angle of explo-sively formed projectiles. The research shows that the foam density is the best at 0.04g/cm3. With the decrease of the density and the in-crease of the foam's flameproof performance, the detonation wave interference increases.