Enzymes can catalyze the oxidative cross-linking of proteins， and there is molecular interaction between polysaccharides or polyphenols with proteins. In order to enhance the application range of casein（CA） edible film， the effects of transglutaminase （TG enzyme）， epigallocatechin gallate （EGCG） and chitosan （CS） on film structure and properties were studied. The particle size and zeta-potential of the film solution were measured， and the mechanical properties， color and water vapor permeability of the composite film were characterized. The results showed that TG enzyme， EGCG and CS all had significant effects on the film structure， and the CAEC group with EGCG and CS added had the best performance among the groups of samples. After adding TG enzyme， the mechanical property of the film was improved， but the water barrier property decreased. After the addition of EGCG， the color of the film darkened， and the tensile strength was improved， but the toughness of film was greatly reduced. After the addition of CS， the tensile strength of the film increased， and its toughness also decreased. After adding both EGCG and CS， the film not only had good tensile strength but also exhibited certain water vapor barrier ability. It exhibited stronger free radical scavenging ability compared with other composite films， and its toughness decreased compared with the original casein film. This study introduced TG enzyme， EGCG and CS to the CA film， which gave it good mechanical properties， free radical scavenging ability and water barrier ability. Overall， this study has some guiding significance for the development of new protein-based edible film.