Ceramic-based microwave absorption (MWA) materials have demonstrated significant application potential in cutting-edge fields, including aerospace and advanced weaponry, owing to their superior mechanical strength, excellent chemical and thermal stability, remarkable oxidation and corrosion resistance, outstanding electromagnetic wave (EMW) absorption performance, low density, and high-temperature durability. To further improve the performance of these materials, structural optimization has emerged as a widely adopted strategy. This review systematically summarizes recent advances in ceramic-based MWA materials across multiple scales, from the nanoscale and microscale to the macroscale, and establishes interconnections among synthesis techniques, structural design, and electromagnetic (EM) behavior. The effects of structural engineering, defect modulation, and hierarchical porosity on the dielectric and magnetic loss mechanisms are discussed, along with how morphology influences impedance matching and attenuation efficiency. Finally, the challenges and future prospects of developing lightweight, broadband, and high-temperature-resistant ceramic absorbers are outlined, providing insights for the intelligent design of next-generation EMW absorption systems.