Abstract: The present invention belongs to the technical field of degradable materials and relates to a biodegradable material. Specifically, the present invention relates to a cellulose acetate-based degradable composite material and a film product thereof, and a preparation method and application thereof. The biodegradable material comprising: a) cellulose acetate and at least one biodegradable polyester material; and b) at least one compatibilizer that can improve interfacial compatibility between cellulose acetate and biodegradable polyester. The biodegradable composite material containing cellulose acetate and polyester has the beneficial effects of improving tensile strength of blends, increasing Young's modulus, and maintaining break elongation.