a method of manufacturing an optical film includes : providing a template ; coating an aluminum film on one surface of the template ; electrolyzing the aluminum film and generating a plurality of regular microstructures on the aluminum film ; providing a substrate ; transferring the microstructures of the template to the substrate to form a plurality of microstructures on the substrate ; and modifying the surfaces of the microstructures of the substrate to obtain a layer containing hydrophobic functional groups on the surfaces of the microstructures of the substrate .