BN-based composites are considered primary candidate materials for twin-roll thin-strip continuous casting and rolling processes. In this study, a novel BN-ZrO 2 composite reinforced with multi-scale SiC particles—wherein coarse particles serve as a structural skeleton and fine particles contribute to densification and grain refinement —was fabricated via spark plasma sintering. The resulting composite exhibits optimal flexural strength, fracture toughness, and Vickers hardness of 257 ± 9.2   MPa, 2.81 ± 0.06   MPa·m 1/2, and 1.55 ± 0.06   GPa, respectively, representing improvements of 125.4%, 75.6%, and 474% over the baseline sample. These improvements are attributed to grain refinement and interfacial reinforcement for strengthening, as well as crack deflection induced by coarse SiC particles and BN-mediated crack bridging for toughening. Furthermore, the improved wear resistance is associated with a transition from brittle fracture to hybrid wear mechanisms involving adhesion, oxidation, and abrasion, resulting in a 57.5% reduction in wear rate to 1.09 × 10 -3 mm 3 N -1 m -1. Additionally, the enhanced oxidation resistance is attributed to the increased relative density and the formation of a continuous and dense SiO 2 oxidation layer that effectively inhibits oxygen diffusion. Meanwhile, the optimized corrosion resistance is achieved through the collaboration of multi-scale SiC grains that effectively minimize reactions between SiC and molten steel.