With the advancement of the “Dual Carbon” strategy, circulating fluidized bed (CFB) ash has become an important research direction for solid waste resource utilization due to its large amount of production, complex component and urgent treatment needs. This paper reviews the composition and characteristics of CFB ash, focusing on its expansion characteristics and loose structure, and summarizes the low-carbon application status and high value-added utilization research of CFB ash in the fields of cement-based materials, geopolymers, road base materials, aerogel preparation and zeolite preparation. The research shows that CFB ash has significant advantages in improving the mechanical properties of cement-based materials, optimizing microstructure and improving durability. Although there are questions such as expansion caused by high sulfur content and high calcium content, the potential of CFB ash as geopolymer and high value-added functional material is gradually explored through physical or chemical modification technology, and the application value can be significantly improved. In the future, researchers should strengthen the research and development of modification technology and the exploration of resource recycling path, promote the application of CFB ash in low-carbon circular economy, and provide theoretical basis and technical support for the sustainable utilization of industrial solid waste.