Abstract: With the rapid advancement of radar sensing technologies, radar stealth technology has emerged as an active area of research in modern military science. As one of the core materials for stealth applications, electromagnetic wave–absorbing materials play a crucial role in enhancing the stealth capability of military equipment. Among them, microwave-absorbing honeycomb structures, as typical structural absorbers, effectively integrate load-bearing and electromagnetic absorption functions. Owing to their excellent broadband absorption performance, lightweight characteristics, and favorable mechanical properties, these materials exhibit remarkable advantages in the design of electromagnetic functional structures and composite materials. Meanwhile, the development of absorbing honeycombs is progressing toward lightweight design, broadband response, multifunctional integration, and intelligent or adaptive capabilities. This paper systematically reviews various types of absorbing honeycombs and their fabrication methods, with emphasis on recent advances in wall-coated, filling-type, and novel absorbing honeycombs, thereby providing theoretical guidance for the further research and development of microwave-absorbing honeycomb materials.