Abstract: The purpose of this paper is to study the application of a fresh preservation mode of composite film-photodynamic technology to delay the quality deterioration of Litopenaeus vannamei. Composite films (PsC and PsG) were prepared by loading curcumin and curcumin/chitosan granules, respectively, onto chitosan as the film-forming matrix. For the preservation of Litopenaeus vannamei, the photosensitive characteristics of two composite films and their mediated photodynamic sterilization (PsC-L/PsG-L) were explored. We covered Litopenaeus vannamei with PsC films and PsG films, respectively, and kept them at 4 °C for 0~4 days after irradiating them with a 420 nm LED light source for 10 minutes. Throughout the storage period, the preservation impact of the composite films was examined comprehensively by assessing the changes in physicochemical indicators such as total bacterial colony, volatile salt nitrogen, pH, texture, and free amino acids in Litopenaeus vannamei. Results indicated that PsG-L and PsC-L might alter the development of microorganism of Litopenaeus vannamei over a 4-day storage period. PsG-L inhibited the increase of TVB-N and pH in Litopenaeus vannamei, delayed texture softening, and had a greater preservation effect than PsC-L. Over a 2-day storage period, PsG-L treatment was more successful than PsC-L in preserving fresh amino acids and reducing the amount of bitter amino acids. Both composite films exhibit photosensitive qualities and photodynamic inhibition of freshness induced by a light source with a wavelength of 420 nm, and they effectively preserve Litopenaeus vannamei. These findings give support for the promotion and deployment of photodynamic non-thermal sterilizing technology in the preservation of aquatic products.