<p>The volume of discarded thermosetting epoxy composites is increasing. Traditional landfill disposal not only pollutes the environment, but also generates significant resource waste. Promoting their degradation and recycling has emerged as a critical problem for industry sustainability. This work uses ester-based epoxy resins as monomers to rapidly degrade thermosetting ester-epoxy/amine cures in mild circumstances. After concentration and filtration, components such ethylene glycol, sodium carboxylate salts, and nitrogen-containing polyols can be easily extracted from the degradation solution. Specifically, sodium carboxylate salts can be re-synthesized into epoxy resins with identical molecular structures to the original epoxy resin via acidification and epoxidization. Purified regenerated nitrogen-containing polyols combine with diphenyl phosphonyl chloride to form a new flame retardant. When incorporated into standard bisphenol A epoxy/anhydride curing systems at a 25 wt% concentration, this flame retardant elevates the flame retardancy rating from non-rated to V-0 compared to untreated epoxy/anhydride cures, the limiting oxygen index reaches 28.7%, while total smoke release decreases by 12.3%. Concurrently, the mechanical properties of the cured material improved, with tensile strength increasing by 32.8% and elongation at break rising by 50.8%, demonstrating excellent overall performance. Building on previous research that demonstrated the rapid deterioration of ester-based epoxy/amine cured materials and the efficient recovery of sodium carboxylate from degradation solutions, this study enhanced the degradation rate of ester-based epoxy/amine cured materials. Simultaneously, nitrogen-containing polyols found in breakdown products were recovered and reused, resulting in complete recovery and usage of all components from ester-based epoxy/amine cured composites.</p>