The invention discloses a preparation method of a high-performance organic-inorganic composite film. The high-performance organic-inorganic composite film is formed by compounding chitin, montmorillonoid and polyvinyl alcohol. Through a one-step reaction, after a nano chitin solution, a montmorillonoid solution and a polyvinyl alcohol solution are adequately mixed, a curtain coating film formationmethod is used for forming the high-performance organic-inorganic composite film. The method has the advantages of low cost, simple process, and easy industrial production; in addition, the preparedcomposite film has the characteristics of heat resistance, light transmission, biodegradability and the like.