A　series　of　catalytic　filters　(Mn-Fe-CeOx/PPS)　with　satisfactory　NO　conversion　and　physical　properties　were　synthesized　by　the　redox　method.　The　Mn-Fe-Ce　ternary　catalyst　system　and　corresponding　oxidation-reduction　equation　were　established　by　using　the　low-valent　oxidation　characteristics　of　cerium　and　iron　to　react　with　high-valent　manganese　capable　of　reduction.　Furthermore,　the　optimal　catalytic　filter　synthesized　under　the　guidance　of　reaction　principles　has　excellent　physicochemical　properties　such　as　high　NO　conversion　(100　%　at　180　degrees　C),　high　stability,　low　loading　capacity　(66.8　g/m2),　and　strong　binding　ability,　making　it　suitable　for　complex　operating　conditions.　Particularly,　in　the　Mn-Fe-Ce　ternary　catalyst　system,　the　coexistence　of　Ce4+　and　Ce3+　causes　the　formation　of　surface　oxygen　vacancies,　uneven　local　charge　distribution　and　additional　chemisorbed　oxygen,　which　are　conducive　to　the　low-temperature　selective　catalytic　reduction　(L-T　SCR)　reaction.　Meanwhile,　there　are　also　high　valence　Mn4+　and　Fe3+　in　catalyst　system,　which　can　promote　the　oxidation　of　NO　and　further　improve　the　L-T　SCR　reaction.