Reflection filters have various applications in optical communication and other systems. In this letter, we propose a narrowband high-reflection filter composed of dielectric and metallic layers, in which an optimized filter combined with an admittance-matching layer with broad stop band is achieved. The structure can be expressed as Sub j (HL)13H2L(HL)313Cr0.84H j air, with full-width at half-maximum (FWHM) bandwidth of 2.5 nm. Based on this structure, reflection filters with multi-peaks are presented, and the law of distribution of peak positions is drawn.