The invention relates to an ethylene adsorption nano titanium dioxide polylactic acid film with wide spectral response, which can be used for fresh keeping of fruits and vegetables, and belongs to thefield of food packaging. The preparation method comprises the following steps: the aperture and porosity of nano titanium dioxide is improved by adopting acid/alkali soaking treatment; chlorophyll loading treatment is adopted to improve the response of the nano titanium dioxide to visible light, and then silane coupling agent modification is performed to promote dispersion of the nano titanium dioxide in a polylactic acid film; and the nano titanium dioxide polylactic acid blend film is prepared by adopting a melting hot-pressing method. The method is simple and easy to operate, the obtainedblend film has excellent mechanical properties, barrier properties and ethylene adsorption capacity, the storage quality of the fruits and vegetables can be effectively improved, and the economic benefits of enterprises are improved.