The simulation model parameters were calibrated based on the results of the perforation experiments, enabling a numerical simulation study of double-layer spacer steel targets subjected to normal/oblique perforation by composite projectile. A comparison and analysis of the perforation process between composite projectiles and single projectiles was conducted, revealing the deformation and failure process of the cap. Additionally, the perforation process and ballistic characteristics of composite projectiles were obtained. The results indicate that there is minimal ballistic deflection, stable projectile attitude, high storage speed, and low overload when the projectile perforates the double-layer spacer plate at high velocity using a composite structure. The cap deforms to protect the head of the main stage, significantly reducing changes in attitude angle and maintaining projectile stability behind the target. Compared to single projectiles, composite projectiles can maintain the attitude stability regardless of whether with an angle of attack when perforating a plate.