Deepwater shaft sealing materials are one of the critical core technologies limiting the advancement of deepwater equipment. Silicon carbide (SiC) ceramics, due to their outstanding high modulus, high thermal conductivity, low density, and excellent corrosion resistance, have become an ideal choice for next-generation deep-sea sealing materials. The immense seawater pressure in deep-sea environments causes significant differences in corrosion and wear processes compared to conventional atmospheric pressure conditions. However, research on the corrosion and wear behavior of SiC ceramics in deep-sea environments remains relatively insufficient. In this study, the static pressure of artificial seawater was adjusted to simulate deep-sea conditions at depths ranging from 0 to 5 km. In-situ characterization of the materials’ performance in deep-sea environments was conducted, and the influence of static pressure on their corrosion and wear properties was explored. The results indicated that SiC ceramics exhibited outstanding corrosion resistance in deep-sea environments at depths between 0 and 5 km. After immersion for 200 h, no significant corrosion, oxidation, or seawater salt-related erosion was observed on the material’s surface, and no mass loss occurred. As seawater depth increased, the chemical reaction between SiC and water gradually weakened, further enhancing the corrosion resistance of SiC ceramics. After seawater corrosion, the mechanical properties of SiC ceramics remained stable. Flexural strength of the material decreased by less than 5% after 200 h-corrosion in a 5 km deep-sea environment, and Vickers hardness or fracture toughness changed little. Under seawater lubrication conditions, SiC ceramics exhibited excellent wear resistance, with a wear rate of 2×10^-8-4×10^-8 mm³/(N·m), much lower than that of the paired silicon nitride (Si₃N₄) ceramic material (4×10^-5-1×10^-4 mm³/(N·m)). Notably, as seawater depth increased, both the material’s resistance to water corrosion and the lubricating load-bearing capacity of seawater were significantly enhanced, leading to a decrease in wear rate with increasing depth. In conclusion, SiC ceramics demonstrate significant potential for application in deep-sea sealing technologies.