A manufacturing method of a polymer film with the photonic crystal structure includes a mixing step for at least mixing an achiral liquid crystal (LC), a chiral dopant, a monomer and a photo initiator together to form an LC-monomer mixture, at least one exposure step for exposing the LC-monomer mixture through a mask, at least one diffusion step for diffusing the monomer from the area around one of the exposure areas to the exposure area, and a LC removing step for removing the achiral LC to form the polymer film. By implementing the diffusion step after the exposure step, the polymerization rate of the monomers is enhanced so as to increase the proportion of the polymer in the polymer film and raise the imprint rate of chirality. Therefore, the polymer film can reveal stronger photonic crystal structure and property of Bragg reflection when it is not filled with any fluid.