The　supercritical　CO2　(SCO2)　power　cycle,　which　is　highly　efficient　and　cost　effective　and　features　a　compact　structure,　is　expected　to　replace　steam　Rankine　cycle　and　bring　technological　revolution　to　coal-fired　power　plants.　To　obtain　the　quantitative　energy　saving　potentials　of　the　SCO2　power　cycle,　this　study　compared　the　thermodynamic　performances　of　coal-fired　power　plants　with　SCO2　cycle　and　10　in-service　coal-fired　power　plants　with　steam　as　the　working　fluid.　The　efficiencies　of　538　°C,　566　°C,　and　600　°C　typical　power　plants　were　increased　by　the　SCO2　cycle　by　2.52%,　2.39%,　and　2.84%,　respectively.　Exergetic　analysis　revealed　that　the　decrease　in　heat　transfer　irreversibility　in　the　boilers　mainly　caused　the　efficiency　enhancement.　Then,　the　main　devices’　performance　parameters,　including　the　isentropic　efficiency　of　the　compressor,　isentropic　efficiency　of　the　turbine,　pressure　drops　of　the　heat　exchangers,　regenerator　terminal　temperature　difference,　and　leakage　ratio,　were　analyzed　in　terms　of　their　sensitivity　to　the　efficiency　enhancement　of　coal-fired　power　plants　integrated　with　the　SCO2　cycle.　The　influence　of　these　parameters　on　the　internal　irreversibility　of　coal-fired　power　plants　was　also　studied.　With　a　600　°C　power　plant　as　an　example,　the　energy　saving　limits　of　the　main　devices’　parameters　of　SCO2　cycle　in　comparison　with　the　steam　Rankine　cycle　are　as　follows:　the　compressor　isentropic　efficiency　exceeded　75%,　the　turbine　isentropic　efficiency　exceeded　86%,　the　pressure　drop　of　the　heat　exchanger　was　less　than　0.35　MPa,　the　temperature　difference　of　the　regenerator　terminal　was　less　than　21　°C,　the　leakage　ratio　was　less　than　2.5%　when　the　leakage　was　not　recovered,　and　the　leakage　ratio　was　less　than　16%　when　the　leakage　was　recovered.　©　2019　Elsevier　Ltd