Abstract: Flexible ablative composites are key thermal protection materials for aerospace equipment serving in extreme high-temperature environments. Currently, the material systems mainly based on ethylene propylene diene monomer and silicone rubber face three critical challenges: it is difficult to synergistically improve thermal protection performance and lightweighting, the filler-matrix interface compatibility is poor, and the ablation mechanism under actual working conditions remains unclear. Adding a large amount of inorganic fillers to improve ablation resistance tends to cause problems such as uneven filler dispersion and weak interfacial bonding between fillers and matrix, which exacerbates the imbalance between performance and density. Additionally, the ablation mechanism under real working conditions remains undetermined, making it impossible to essentially reveal the structural evolution and failure laws during the ablation process, and failing to provide theoretical support for precise interface regulation and synergistic design of performance and lightweighting. This paper reviews the research progress of flexible ablative composites in matrix modification, interface regulation and ablation mechanism in recent years, and focuses on analyzing the structure-activity relationship between matrix, interface and ablation behavior, aiming to provide theoretical reference for breaking through the bottleneck of synergistic design of thermal protection performance and lightweighting and developing high-performance flexible thermal protection materials.