Abstract: Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder (CIP) with TiO₂ was designed. Given the TiO₂ coating, the Z of the CIP@TiO₂ composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO₂ was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO₂ composite was improved substantially, the minimum reflection loss reached −46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO₂ showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO₂ was about 400°C, whereas the uncoated CIP had an oxidation starting temperature of approximately 250°C. Moreover, the largest oxidation rate temperature of CIP@TiO₂ increased to around 550°C. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.