The invention relates to a preparing 
photon crystal film method, wherein, the mechanical intension and the 
solvent resistance of the 
photon crystal film can be improved. In the method, the 
polymer monomer solution which is adulterated with 
photoinitiator and 
cross linker can evenly permeate into interspaces of the 
photon crystal film with an opal type structure, and then the film can be irradiated by 
ultraviolet light to make the 
polymer monomer polymerized; after the 
polymer monomer is polymerized, the 
emulsion particle bulbs in the 
photon crystal film with a opal type structure can be jointed firmly, a polymer 
macromolecule net can be formed among the 
emulsion particle bulbs, the performance of the phone crystal can be enhanced through utilizing the net structure which is formed by the polymer 
macromolecule chains, therefore, the mechanical performance of the 
photon crystal film can be enhanced. Taking the rigidity of the film and Young modulus for example, the polymer monomer solution can permeate in the interspaces of the 
photon crystal film with an opal type structure, through the 
processing of photo-cross linking, the 
mechanical property of the rigidity of the photon crystal film, the Young modulus and the like and the 
solvent resistance can be improved greatly, and the initial 
mechanical property can not be essentially effected.