As the thermal energy dissipation and environmental pollution intensify, light-weight and biodegradable thermal insulation materials have gained significant attention. Poly(butylene adipate-co-terephthalate) (PBAT) foams, renowned for their exceptional biodegradability and thermal insulation properties, could serve as a promising material for thermal insulation. Regrettably, the insufficient foamability and inherent shrinkage behavior of PBAT foams continue to be major obstacle in developing high-performance flexible PBAT foams. In this study, epoxidized soybean oil (ESO) was grafted onto the PBAT/PLA by the ring-opening reaction to achieve micro-crosslinked structures and induce the formation of PBAT fibers within the PBAT/PLA blend. Then, further CO