Abstract: Nano-TiO₂ was modified and characterized, then added to the chitosan film in the solution, in order to improve the performance and antibacterial function of the film, and extend the preservation time of the composite film for fruits and vegetables. The results showed that the modified nanometer TiO₂ had changes in crystal shape and structure. When the modified Nano- TiO₂ was added to the film, CO₂ coefficient of the optimized composite film reduced by 24% compared with blank film, permeable rate was reduced by 65.5%, the tensile strength increased by 13.99%, the elongation at break increased by 50% and tear strength increased by 57.89%. In addition, light transmittance was improved in ultraviolet region, bacteriostasis was enhanced, and preservation time of the composite film for fruits and vegetables extended to some extent.