The　supercritical　carbon　dioxide　(SCO2)　power　cycle　is　a　potential　power　cycle　for　coal-fired　power　plants.　In　the　SCO2　power　systems　provided　in　previous　studies,　the　boiler　exhaust　temperature　is　about　120　°C.　To　enhance　the　power　plant　efficiency　and　the　dust　collection　efficiency　of　electrostatic　precipitator,　SCO2　power　systems　should　be　advanced　to　cool　the　boiler　exhaust　fluegas　to　nearly　95　°C.　Therefore,　systems　of　waste　heat　recovery　from　low-temperature　fluegas　are　proposed　and　optimized　in　this　study.　Thermodynamic　and　optimization　models　are　developed.　The　double　reheat　recompression　SCO2　cycle　is　optimized　as　benchmark　system.　The　benchmark　system　is　improved　to　decrease　the　exergy　loss　and　boiler　exhaust,　decrease　the　irreversibility　of　air　preheater,　and　recover　waste　heat　of　the　SCO2　cycle　to　preheat　air　to　the　air　preheater.　When　the　main　compressor　intercooling　or　bypass　fluegas　ahead　the　air　preheater　is　adopted,　the　temperature　of　boiler　exhaust　fluegas　can　be　decreased　to　around　95　°C　which　can　ensure　a　high　dust　collection　efficiency　of　electrostatic　precipitator.　The　power　plant　efficiency　is　also　increased　as　a　result.　However,　if　only　low-temperature　economizer　is　integrated,　then　the　power　plant　efficiency　is　enhanced　slightly　by　0.09%-pts.　If　the　low　temperature　economizer　is　integrated　with　other　system　improvements,　the　power　plant　efficiency　can　be　enhanced　by　0.89%-pts.　Exergy　analysis　is　also　performed　to　reveal　the　mechanisms　of　efficiency　enhancement.　©　2020　Elsevier　Ltd