In　order　to　avoid　the　high　manufacturing　cost　and　ohmic　loss　of　metal　perfect　metamaterial　absorber　(PMA),　and　to　solve　the　problem　that　IMA　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-hand　IMA　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　IMA　grating　respectively.　This　research　can　provide　theoretical　guidance　for　the　preparation　of　high　quality　polarization　independent　medium　narrow　bandwidth　PMA　in　the　future.