▎ 摘　　要

NOVELTY - Three-layer composite biodegradable film with sustained release function comprises a three-layer structure consisting of slow-release films and degradable films alternately, and the degradable film is the middle layer. USE - The biodegradable film is useful in compost bag, agricultural mulching film field, straw, plastic tableware and stirrer, aquatic and land ecological system and biological diversity. ADVANTAGE - The biodegradable film has excellent mechanical performance compared with the single-layer film, and exhibits hydrophobicity, and expands the application range of the composite film. The slow-release layer efficiently protects the degradation layer. The film has efficient synergistic effect, and can be flexibly produced at low cost. The degradation rate of the film is adjusted by adjusting the thickness of the degradable layer in the film, so that the film has slow release effect.