Environmental concerns stemming from the widespread use of polyethylene packaging and the perishability of fresh products have promoted the development of antimicrobial biodegradable packaging films in preservation of vegetables. In this study, antimicrobial films based on chitosan (CS)-nisin (Ni)-nanocrystalline cellulose (NCC) were characterized, and its preservation effect applied to baby cabbage was investigated. The results suggest that 1 % CS-0.6 g/L Ni solution presented the best inhibitory effect on the growth of Pectobacterium carotovorum but the poor dispersion and film-forming properties. Additionally, NCC significantly enhanced the homogeneity of the film-forming solution and the degree of crystallinity in the films. Compared to CS-Ni film, the tensile strength and DPPH radical scavenging of CS-Ni-NCC film were boosted by 14.1 MPa and 4.56 %, and the oxygen and water vapor permeability were reduced by 54.4 % and 12.9 %, respectively. Furthermore, baby cabbage packaged with the CS-Ni-NCC film exhibited the lowest decay rate, weight loss, and appearance deterioration while maintaining better nutrient and antioxidant capacity among all treatment groups. This contributed to delaying the quality deterioration and extending the shelf-life of baby cabbage during storage. The findings reveal that CS-Ni-NCC composite films can be employed as packaging materials for increasing the shelf life of vegetables.