The invention provides a biodegradable high-barrier composite film material structure. The composite film material sequentially comprises a cellulose layer, a pure aluminum layer, a PBAT layer, a first adhesive layer clamped between the PBAT layer and the pure aluminum layer, and a second adhesive layer clamped between the pure aluminum layer and the cellulose layer from top to bottom, wherein the PBAT layer, the first adhesive layer, the pure aluminum layer, the second adhesive layer and the cellulose layer are combined together through a composite film forming technology. The cellulose layer with printing adaptability, temperature resistance, poor extensibility and no heat sealability and the pure aluminum with high barrier property are compounded together through the second adhesive layer, and then are compounded together with the PBAT layer with heat sealability and extensibility through the first adhesive layer, so that the properties of the cellulose layer and the PBAT layer are complementary, and the composite film material which is good in surface wetting tension, resistant to temperature, capable of being subjected to heat sealing and capable of meeting the performance requirements of low-temperature freezing, high-barrier conditions and the like can be prepared. The degradation rate of the degradable part is 90% or above, and energy saving and environment friendliness are achieved.