Abstract: Ballistic ceramics are widely used in composite armor owing to their high hardness and low density. Metal encapsulation structures suppress crack propagation by applying three-dimensional confinement to ceramics and introducing prestress. In this study, explicit dynamic finite element models of equal-mass Type Ⅰ (single SiC layer + dual TC4 encapsulation) and Type Ⅱ (dual SiC layers + triple TC4 encapsulation) TC4/SiC three-dimensional prestressed constrained composite structures were established, and the effects of structural parameters on the prestress field distribution and anti-penetration performance were systematically analyzed. Results show that increasing SiC layer thickness weakens the three-dimensional confinement of the TC4 layer on the internal ceramics, and adjusting the TC4 thickness ratio can also significantly influence the SiC prestress level. Although increasing backing plate thickness reduces the internal prestress of ceramics, the enhanced backing support effect effectively suppresses early tensile delamination of ceramics and substantially improves ceramic pulverization energy absorption, with this enhancement effect dominating the improvement in anti-penetration performance. In the optimal Type Ⅱ configuration (thickness ratio T₂∶T₄ = 5∶1, T₁∶T₃∶T₅ = 2∶2∶17), the specific energy absorption (SEA) of the T₄ ceramic layer increases by 247.5% compared to the baseline case, and the projectile residual mass decreases by 9.3% relative to the optimal Type Ⅰ configuration, demonstrating superior weight reduction potential. Furthermore, the blunt-nose projectile tends to undergo plastic upsetting during the initial penetration phase, resulting in stronger erosion of the projectile by the front ceramic layer; stress concentration at the tip of the conical-nose projectile causes premature ceramic fracture and early transfer of impact load to the rear structure, with the projectile residual velocity 7.9% higher and residual mass 4.1% greater than in the blunt-nose projectile case.