The　technology　for　the　selective　catalytic　reduction　of　NOx　by　CO　(CO-SCR)　has　the　capability　to　simultaneously　eliminate　CO　and　NOx　from　industrial　flue　gas　and　automobile　exhaust,　thus　making　it　a　promising　denitrification　method.　The　advancement　of　cost-effective　and　high-performing　catalysts　is　crucial　for　the　commercialization　of　this　technology.　Mn-based　catalysts　demonstrate　enhanced　catalytic　efficiency　under　conditions　of　low　temperature　and　low　oxygen　content　when　compared　to　other　transition　metal-based　catalysts,　indicating　significant　potential　for　practical　applications.　This　review　outlines　the　diverse　Mn-based　catalysts,　including　bulk　or　supported　MnOx　catalysts,　bulk　or　supported　Mn-based　composite　oxide　catalysts,　and　the　use　of　MnOx　as　dopants.　Subsequently,　the　synthesis　methods　and　catalytic　mechanism　employed　by　Mn-based　catalysts　are　presented.　The　following　section　examines　the　impact　of　O-2,　H2O,　and　SO2　on　the　catalytic　performance.　Finally,　the　potential　and　implications　of　this　reaction　are　deliberated.　This　work　aims　to　offer　theoretical　guidance　for　the　rational　design　of　highly　efficient　Mn-based　catalysts　in　the　CO-SCR　reaction　for　industrial　applications.