Perovskite　solar　cells　have　gradually　become　the　most　attractive　alternative　for　next-generation　photovoltaic　devices　due　to　their　excellent　photovoltaic　conversion　efficiencies　and　low　manufacturing　costs.　Defect　engineering　is　an　essential　topic　for　improving　the　performance　of　perovskite　devices.　In　this　study,　we　utilize　a　bifunctional　alkylamine　sulfonate　to　modify　the　perovskite　interfaces.　The　TsO-　of　sulfonates　coordinates　with　Pb2+,　while　-NH2　of　alkylamine　forms　hydrogen　bonds　with　iodine,　which　reduces　charge　recombination　and　improves　energy　level　arrangement.　The　molecular　size　and　the　alkylamine＇s　dielectric　constant　significantly　influence　the　interface　modification　performance.　For　the　champion　device　with　BATsO　treatment,　there　is　an　enhancement　in　both　the　fill　factor　and　the　open-circuit　voltage,　resulting　in　a　power　conversion　efficiency　(PCE)　of　23.53%.　After　400　h　of　working　condition,　the　device　maintains　roughly　90.40%　of　its　initial　efficiency.　Therefore,　this　study　postulates　that　modifying　bifunctional　alkylamine　sulfonates　could　effectively　enhance　the　PSC＇s　performance.