High-performance structural microwave absorbing ceramic matrix composites represent an ideal candidate for achieving the integration of broadband wave absorption and high load-bearing capacity in aerospace high-temperature components. Taking the multi-scale collaborative design of macro-meso-micro levels as the core research approach, this paper systematically summarizes the fundamental design principles of high-performance structural microwave absorbing composites. From the perspective of material design, it comprehensively considers the optimal balance between impedance matching and electromagnetic loss to achieve broadband and efficient absorption of electromagnetic waves. The study deeply investigates the influence mechanisms of micro-component materials (such as SiC, Si3N4, ceramic matrices, and carbon nanotubes, metal oxides as absorbers) on the microwave absorbing performance of composites. It also analyzes the key roles of typical macro-mesoscopic configurations (such as layered structures, porous structures, and fiber-reinforced structures) in regulating electromagnetic wave absorption. By establishing correlation models between multi-scale structures and performance, a series of optimized design methods for high-performance SACMCs are summarized, covering material composition selection, structural parameter optimization, and other dimensions. This research provides critical theoretical foundations and practical guidance for the integrated design and performance evaluation of high-temperature broadband microwave absorbing systems in the new generation of aerospace vehicles. It holds significant implications for promoting the collaborative development of stealth technology and structural materials in the aerospace industry.