Abstract: To investigate the influence of backplate mechanical properties on the formation mechanism of ceramic cones in boron carbide ceramic composite armor, four typical backplate materials (6061 aluminum alloy, 7075 aluminum alloy, T300 carbon fiber board, and UHMWPE) were selected. A combination of ballistic impact tests using a one-stage light gas gun and LS-DYNA numerical simulations was employed to systematically study the regulatory effects of backplate yield strength, stiffness, and wave impedance on the morphology and evolution of ceramic cones. The results indicate that: 1) The load transfer from the ceramic cone to the backplate is not solely dependent on a single outer cone but is achieved through the synergistic action of multiple cracks, including the outer and inner cones; 2) The yield strength of the backplate has no significant effect on the crack propagation of the main cone; 3) Regarding stiffness, the outer cone angle decreases linearly with increasing elastic modulus, while the inner cone angle increases exponentially; 4) Wave impedance alters the internal stress field of the ceramic by regulating stress wave reflection/transmission, resulting in a linear increase in the inner cone angle and an exponential decrease in the outer cone angle with increasing impedance.