Exciton　binding　energy　has　been　regarded　as　a　crucial　parameter　for　mediating　charge　separation　in　polymeric　photocatalysts.　Minimizing　the　exciton　binding　energy　of　the　polymers　can　increase　the　yield　of　charge-carrier　generation　and　thus　improve　the　photocatalytic　activities,　but　the　realization　of　this　approach　remains　a　great　challenge.　Herein,　a　series　of　linear　donor–acceptor　conjugated　polymers　has　been　developed　to　minimize　the　exciton　binding　energy　by　modulating　the　charge-transfer　pathway.　The　results　reveal　that　the　reduced　energy　loss　of　the　charge-transfer　state　can　facilitate　the　electron　transfer　from　donor　to　acceptor,　and　thus,　more　electrons　are　ready　for　subsequent　reduction　reactions.　The　optimized　polymer,　FSO-FS,　exhibits　a　remarkable　photochemical　performance　under　visible　light　irradiation.　©　2019　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim