In recent years, with the rapid development of electronic devices, electromagnetic pollution has become increasingly severe, threatening the normal operation of electronic equipment and posing significant risks to information security. In the field of military radar stealth, the development of high-temperature absorbing materials with "thin, light, wide, and strong" characteristics along with high mechanical strength, heat resistance, corrosion resistance, and oxidation resistance becomes a critical scientific challenge urgently requiring resolution to reduce radar detection capabilities against military equipment and enhance adaptability in complex environments.

However, magnetic materials lose their magnetism in high-temperature environments, thereby reducing their ability to dissipate electromagnetic waves. Conductive loss-type materials, primarily composed of carbon, are prone to oxidation when exposed to air for extended periods, which diminishes their conductivity and consequently weakens their wave-absorbing performance. Si—O—C ceramics are a type of high-temperature ceramic with an open polymeric network structure composed of free carbon phases and amorphous Si—O—C glass phases. These ceramics exhibit some advantages such as high-temperature resistance, oxidation resistance, and excellent mechanical strength, making them a potential candidate for high-temperature wave-absorbing materials. Among the various methods for preparing Si—O—C ceramics, the precursor conversion method is widely used due to its simple process, broad range of matrix composition adjustments, and high conversion efficiency.

This review represents the preparation of particle-reinforced Si—O—C ceramic composite microwave absorbing materials, porous Si-O-C ceramic absorbing materials, and hetero-element modified Si—O—C ceramic absorbing materials via the precursor conversion method. It introduces the fabrication of fiber-reinforced Si—O—C ceramic composite absorbing materials, including C_f/Si—O—C ceramics, SiC_f/Si—O—C ceramics, and oxide fiber/Si—O—C ceramics, achieving a structural-functional integration. Compared to single-phase Si—O—C ceramic materials, Si—O—C ceramic composites exhibit superior dielectric properties and balance multiple loss mechanisms and impedance matching, thereby enhancing microwave absorption performance. In addition, the future development directions of Si—O—C ceramic composite absorbing materials are also discussed.