To overcome the insufficient corrosion resistance of 35CrMo steel, a superhydrophobic MAO/PDMS-SiO 2 composite coating was prepared by integrating micro-arc oxidation (MAO) with a spray-coating process, aiming to substantially improve its corrosion protection capability. The composite coating exhibits excellent wetting behavior, with a static water contact angle of 160.6° and a rolling angle of 3.59°. The coating's microstructure, elemental distribution, and phase composition were comprehensively characterized through scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The corrosion-failure behavior was assessed through a 504-hour neutral salt spray test (NSS), while potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) were employed to elucidate the evolution of protective performance and failure mechanisms under three conditions: the as-prepared state, prolonged neutral salt spray exposure, and mechanical friction-induced damage. The corrosion current density of the MAO/PDMS–SiO 2 composite coating was measured at 7.23 × 10 −9 A·cm −2, four orders of magnitude lower than that of the bare 35CrMo steel substrate. The results reveal that the composite coating markedly improves both the corrosion resistance and post-damage stability of 35CrMo steel, owing to the synergistic contributions of superhydrophobicity and barrier functionality. This study presents a viable and novel strategy for protecting 35CrMo steel against corrosion, with promising application potential in marine engineering and heavy-duty machinery.