Oxy-combustion　is　one　of　the　most　promising　technology　for　CO2　capture　in　coal-fired　power　plants.　However,　under　oxy-combustion　conditions,　the　concentrations　of　acid　gas　species　are　significantly　increased　due　to　the　introduction　of　the　flue　gas　recycle,　which　aggravates　the　high-temperature　corrosion　of　heat　exchanger　materials　in　boilers.　In　this　study,　the　early-stage　high-temperature　corrosion　(0–16　h)　of　two　representative　water-wall　tube　materials　(20G,　12Cr1MoV)　is　experimentally　tested　in　a　lab-scale　furnace　with　the　simulated　oxy-combustion　atmosphere.　The　effects　of　material,　temperature,　CO2,　H2O,　SO2,　H2S　and　CO　atmospheres　on　high-temperature　corrosion　behaviors　is　investigated.　The　micro-morphologies　and　compositions　of　corrosion　layers　are　characterized　by　scanning　electron　microscope　with　energy　dispersive　X-ray　spectra　(SEM-EDS)　and　X-ray　diffraction　(XRD).　Kinetic　analysis　shows　that　the　high　concentration　of　CO2　accelerates　high-temperature　corrosion　of　water　wall　materials.　In　the　simulated　oxy-fuel　combustion　atmosphere　(CO2/O2/SO2),　the　mass　gain　rate　can　be　enhanced　by　10%–30%　compared　to　the　conventional　air　combustion　atmosphere　(N2/O2/SO2),　and　the　major　composition　of　oxide　scale　is　magnetite.　In　a　reducing　oxy-fuel　atmosphere　(CO2/CO/SO2/H2S),　the　major　components　of　oxide　scale　are　magnetite　and　ferrous　sulfide.　The　high　concentration　of　moisture　in　the　atmosphere　accelerated　the　corrosion　rate　by　10–30%.　For　both　model　alloys,　the　corrosion　kinetics　obey　the　parabolic　law.　Water-wall　tube　material　12Cr1MoV　appears　superiority　in　corrosion　resistance　compared　with　20G　material.　©　2020　Energy　Institute