Abstract: The increasingly severe environmental problems caused by the abuse of petroleum-based plastics and the increasing shortage of nonrenewable petroleum resources have led to the emergence of biopolymer-based materials. Starch is biodegradable and renewable and can be used as a good substitute for petroleum bases. However, further commercial application of starch-based biodegradable films is limited by their poor mechanical properties and hydrophilicity. Therefore, the physical or chemical modification of starch is one of the main methods to improve the properties of films. In this review, the multiscale structural properties of starch are introduced, and the modification methods and current research of starch for preparing biodegradable films are reviewed. The effects of modification methods on the mechanical properties, water vapor permeability, transparency and biodegradability of starch-based films are mainly introduced. The properties of starch-based materials determine the direction of their application. Finally, the application of starch-based biodegradable fims is described. The study of the properties of modified starch-based films provides a theoretical basis for improving the properties of starch-based films.