The　selective　catalytic　reduction　of　NO　by　CO　(CO-SCR)　is　regarded　as　a　highly　promising　technology　for　the　purification　of　industrial　exhaust　gas　due　to　its　ability　to　simultaneously　eliminate　two　toxic　and　harmful　gases.　This　review　provides　an　overview　of　recent　advances　in　the　CO-SCR　reaction,　firstly　exploring　the　multiple　reaction　pathways　for　the　reduction　of　NO　to　N2　by　CO,　and　then　analyzing　in　depth　the　multidimensional　influence　mechanisms　of　O2,　SO2　and　H2O　on　this　reaction.　In　addition,　the　structural　control　strategies　to　improve　the　resistance　of　noble-　and　non-precious　metal-based　single-atom　and　cluster　catalysts　to　O2,　SO2　and　H2O　were　discussed　from　the　perspectives　of　particle　size　regulation,　electronic　structure　control,　and　surface/interfacial　structure　modulation.　Finally,　the　paper　summarizes　the　current　challenges　of　CO-SCR　technology　and　provides　detailed　suggestions　for　future　research　directions,　with　the　objective　of　enriching　the　design　concepts　for　high-　efficiency　denitrification　catalysts.