Ni–SiC metal–ceramic composite coatings were deposited onto AISI 1045 steel substrates via cold spraying, and the effects of SiC volume fraction on the coating’s microstructure, mechanical properties, and tribological performance were systematically investigated. The coating exhibited a “hard skeletal phase + soft matrix” architecture, and the dispersion strengthening imparted by the SiC particles increased hardness from 309 HV to 339 HV, with a peak bond strength of 23.7 MPa. Under lubricated conditions and loads of 50–200 N, the friction coefficient remained stable between 0.026 and 0.064. Coatings with higher SiC content exhibited significantly reduced wear due to decreased contact pressure, in situ self-polishing behavior, and the formation of microscale oil reservoirs. SEM, EDS, and finite element simulations revealed that when the SiC embedding depth exceeded 0.5 d, a uniform stress field was generated, preventing interfacial debonding and thereby extending service life. These findings offer a theoretical foundation for the design and engineering application of cold-sprayed wear-resistant coatings.