The　sensing　performance　of　antimonene　towards　SF6　decomposition　gases　was　investigated　by　first　principles　calculations　in　this　paper.　By　analyzing　the　adsorption　energy,　charge　transfer,　work　function　variation,　and　density　of　states　(DOS),　we　concluded　that　antimonene　is　sensitive　and　selective　to　the　SF6　decomposition　gas　product　SO2.　Unlike　previous　studies,　the　effect　of　Stone-Wales　(SW)　defects　and　biaxial　strain　on　the　sensing　performance　of　antimonene　was　also　explored,　indicating　that　SW　defects　can　expand　the　range　of　available　antimonene　sensor　structures　and　that　antimonene　is　highly　stable　to　biaxial　strain.　As　stability　is　one　of　the　main　challenges　that　hinders　the　practical　application　of　sensing　materials,　we　concluded　that　anitmonene　would　be　a　promising　candidate　for　the　development　of　SF6　decomposition　gas　sensors　with　high　sensitivity　and　stability　that　could　replace　other　sensitive　but　unstable　two　dimensional　materials　such　as　phosphorene.