In order to avoid the high manufacturing cost and ohmic loss of metal perfect metamaterial absorber (PMA), and to solve the problem that PMA is sensitive to the polarization state and incident angle of light. A dual channel polarization independent dielectric narrow-band PMA is designed by using low loss dielectric materials, and the theoretical analysis and verification are carried out by using the finite-difference time-domain method. It is found that the absorption wavelength, absorption efficiency, and full-width at half-maximum of the polarization independent medium narrow-band PMA designed in this paper are the same no matter in transverse electric(TE) or transverse magnetic (TM) polarization state. TM and TE polarization can achieve narrow bandwidth and ultra-high absorption at the same wavelength because PMA structure is rotationally symmetric. The reason why PMA can achieve dual channel narrow bandwidth is that Fabry-Perot cavity resonance and guided mode resonance are formed in PMA grating respectively. This research can provide theoretical guidance for the preparation of high quality polarization independent medium narrow bandwidth PMA in the future.