Narrowband high-reflection filter coatings are very important in optical communication and optical detectors. A kind of narrowband high-reflection filter coating with structure of “substrate H(LH)m1αL(HL)m2βCrM air” was proposed, the influences of Cr thickness and two different matching film stacks on the characteristics of the filter coating was discussed, and the distribution of the internal electric field was calculated. Results show that a wider stop band in reflection can be realized with a thicker metallic layer and inserting a matching stack will produce a deep rejection of the stop-band. The matching stack leading to a greater admittance helps obtain a wide stop-band and narrow-band high reflection, and also produces zero electric field intensity in the Cr layer at the central wavelength, which consequently reduces the absorption and enhances the reflectance of the filter.