Abstract: The possibility of designing optical filters using photonic crystals technique was studied in this paper.A dual-channel optical filter was designed using photonic crystal concept and prepared by Ion Beam Assisted Deposition（IBAD）.The influence of thickness error of each layer to optical character was also discussed,and the result shows that the most sensitive layer is defect-layer.So it is possible to design dual-channel filters using one-dimension photonic crystals concept.