Abstract: An environment-friendly slow-release carbon source biofilm carrier material was prepared from agricultural and forestry wastes, wheat straw and polyethylene, and its physical properties, film-hanging properties and nutritional slow-release properties were explored. The results showed that the average strength of the carrier material was 4.5 MPa, molding pressure, thermoplastic time, straw particle size, and straw content all affected the specific gravity of the carrier material, but the specific gravity of the carrier material was less than that of water; The higher the straw content was, the greater the porosity was. The carrier material with 80% straw content had a porosity of 93.29%; The dissolution rate of organic matter in the early stage of the carrier material was small and fast, and the rate of dissolution in the middle and late stages was slowed down. The amount of organic matter dissolution reaches the peak value at 8 d. The higher the straw content was, the higher the organic content of the carrier material leaching solution was. At the peak, the organic content of the carrier material with 80% straw content was 79 mg/（L·g）. The leachate contains abundant elements required by microorganisms, free of all kinds of toxic elements, and could promote the growth of microorganisms.

Key words: biofilm carrier, agricultural and forestry waste, slow release carbon source