Abstract: The transfer matrix method was used to study and design new optical filters and optical switches with high performance and quality, the modulation of optical transmission characteristics of photonic crystal (AB)5ACn(BABAB)CnA(BA)5 by symmetrical double defects were also studied. The result showed that symmetric double defect one-dimensional photonic crystal (AB)5ACn(BABAB)CnA(BA)5 can achieve the function with high transmission, high quality optical filtering and optical switchings. Besides, with the increase of defect period n and incident angle , the blue shift phenomenon occured when the dual-filter channel moved towards the short wave direction, and the distance between the two channels became shorter, but the speed of blue shift of the two channels was different from that of the two channels. With the increase of defect physical thickness dC and refractive index nC, the photonic crystal dual-filter channel moved towards long-wave direction, resulting in red shift phenomenon, and the distance between the two filter channels increased, the redshift speed of the two filter channels was different from that of the distance between the two channels. With the increase of defect period n, physical thickness dC, refractive index nC and incident angle , the transmittance of the two-channel filter remained unchanged at 100%. The optical transmission characteristics of symmetrical double-defect photonic crystals can guide the research and design of high transmittance, high performance and high quality dual-channel optical filters and high sensitivity optical switches.