Pressurized　oxy-combustion　is　one　of　the　most　promising　and　efficient　CO2　capture　technologies　for　coal-fired　power　plants,　which　could　reduce　energy　consumption　for　carbon　capture.　However,　due　to　the　effects　of　pressurization　and　flue　gas　recirculation,　the　partial　pressure　of　sulfur　oxides　(SOx)　in　pressurized　oxy-combustion　is　significantly　higher　than　that　of　air-combustion,　which　leads　to　the　corrosion　risks　and　environment　hazards.　It　is　essential　to　investigate　the　SOx　control　in　pressurized　oxy-combustion.　In　this　paper,　the　in-furnace　calcination　and　desulfurization　characteristics　of　calcium　carbonate　in　pressurized　oxy-combustion　were　carried　out　in　a　pressurized　drop　tube　furnace.　The　findings　show　that　the　sulfation　reaction　in　pressurized　oxy-combustion　is　direct　sulfation　and　the　sulfation　rate　increases　with　the　increase　of　temperature　and　pressure.　The　desulfurization　efficiency　in　pressurized　oxy-combustion　is　lower　than　that　in　atmospheric　air　atmosphere　below　950　°C,　but　it　reverses　above　950　°C,　indicating　that　the　minimum　desulfurization　temperature　in　the　furnace　of　the　pressurized　oxy-combustion　is　higher　than　that　of　atmospheric　air　atmosphere.　Therefore,　limestone　can　still　be　used　as　a　sorbent　in　the　pressurized　oxy-combustion　furnace.　This　study　could　contribute　to　the　design　of　dry　desulfurization　systems　in　pressurized　oxy-combustion　combustors　that　use　fossil　fuel　energies　with　high　efficiency　and　low　SOx　emissions.　©　2022