目的 对壳聚糖进行接枝改性，并与百里香精油复合，探究复合涂膜在荔枝贮藏期间的保鲜效果。方法 在活化剂的作用下，对壳聚糖接枝季磷盐和山梨酸，提高其水溶性和抗菌活性，然后与纳米纤维素、百里香精油制备复合膜液，将复合膜液用于荔枝的常温保鲜，对荔枝的pH、质量损失率、维生素C含量、总酚含量、可滴定酸含量、可溶固形物含量等指标进行测试分析，并与超纯水、咪鲜胺、壳聚糖等对照组进行对比，探究复合涂膜对荔枝贮藏品质的影响。结果 与对照处理组相比，改性壳聚糖/百里香精油复合涂膜具有较好的阻隔性能，能有效减少荔枝的质量损失，减少水分和营养物质的流失量，抑制霉菌的生长与褐变。结论 改性壳聚糖/百里香精油复合涂膜具有保持荔枝质量、延长贮藏货架期的能力，并且涂膜液来源经济，有较高的实用推广性和发展前景，能够实现经济、绿色、高效、持久的保鲜效果。

The work aims to graft chitosan and compound it with thyme essential oil and then study the preservation effect of composite coating on litchi during storage. Activator reagents were utilized to graft chitosan with quaternary phosphate salt and sorbic acid to improve its water solubility and antibacterial activity, and then the composite coating solution was prepared with nano cellulose and thyme essential oil. The composite coating solution was used for the preservation of litchi at room temperature, and the pH, weight loss rate, vitamin C content, total phenol content, titratable acid, soluble solids and other indicators of litchi were tested and analyzed. By comparing the composite coating with the control group treated with ultrapure water, prochloraz, chitosan and other methods, the effect of composite coating on the storage quality of litchi was explored. Compared with the control treatment group, the modified chitosan/thyme essential oil composite coating had better barrier performance, which could effectively reduce the weight loss of litchi, reduce the loss of water and nutrients, and inhibit mold growth and browning. The modified chitosan/thyme essential oil composite coating has the ability to maintain the quality of litchi and extend the shelf life of storage, and the coating solution is economical in source, has high practical popularization and development prospects, and achieves economic, green, efficient and lasting preservation effect.