F-V2O5-WO3/TiO2　catalysts　were　prepared　by　the　impregnation　method.　As　the　content　of　F　ions　increased　from　0.00　to　0.35　wt.%,　the　NO　conversion　of　F-V2O5-WO3/TiO2　catalysts　initially　increased　and　then　decreased.　The　0.2F-V2O5-WO3/TiO2　catalyst　(0.2　wt.%　F　ion)　exhibited　the　best　denitration　(De-NOx)　performance,　with　more　than　95%　NO　conversion　in　the　temperature　range　160-360　degrees　C,　and　99.0%　N-2　selectivity　between　110　and　280　degrees　C.　The　addition　of　an　appropriate　amount　of　F　ions　eroded　the　surface　morphology　of　the　catalyst　and　reduced　its　grain　size,　thus　enhancing　the　NO　conversion　at　low　temperature　as　well　as　the　sulfur　and　water　resistance　of　the　V2O5-WO3/TiO2　catalyst.　After　selective　catalytic　reduction　(SCR)　reaction　in　a　gas　flow　containing　SO2　and　H2O,　the　number　of　NH3　adsorption　sites,　active　component　content,　specific　surface　area　and　pore　volume　decreased　to　different　degrees.　Ammonium　sulfate　species　deposited　on　the　catalyst　surface,　which　blocked　part　of　the　active　sites　and　reduced　the　NO　conversion　performance　of　the　catalyst.　On-line　thermal　regeneration　could　not　completely　recover　the　catalyst　activity,　although　it　prolonged　the　cumulative　life　of　the　catalyst.　In　addition,　a　mechanism　for　the　effects　of　SO2　and　H2O　on　catalyst　NO　conversion　was　proposed.　(C)　2020　The　Research　Center　for　Eco-Environmental　Sciences,　Chinese　Academy　of　Sciences.　Published　by　Elsevier　B.V.