Abstract: The extensive use of traditional plastics and their non-degradable nature after disposal have led to severe pollution in the ecological environment and exerted enormous pressure on the increasingly critical petrochemical energy resources. Thin film material is one of the primary plastic products currently in application. The biodegradable films, known for their environmental friendliness and contribution to achieving carbon cycling goals, hold the potential to make substantial strides in mitigating global environmental pollution and addressing energy shortages. However, biodegradable films face challenges such as suboptimal performance and higher costs, with their poor barrier properties particularly limiting their application in packaging films. This article reviews the current research status of nanomaterials for enhancing the gas barrier properties of biodegradable films. The discussion is divided into three main parts: The types of nanomaterials, their combinations, and the processing methods for producing nanocomposite films. The article also provides insights into the future research and development of biodegradable films.