In　this　work,　four　donor　(D)-acceptor　(A)　copolymers　based　on　benzodithiophene　(BDT)　and　benzothiadiazole　(BT)　with　different　alkylthiolated　and/or　fluorinated　side　chains　are　developed　for　efficient　fullerene　and　nonfullerene　polymer　solar　cells　(PSCs).　The　synergistic　effect　of　sulfuration　and　fluorination　on　the　optical　absorption,　energy　level,　crystallinity,　carrier　mobility,　blend　morphology,　and　photovoltaic　performance　is　investigated　systematically.　By　incorporating　sulfur　atoms　onto　the　side　chains,　a　little　blueshifted　but　significantly　increased　absorption　can　be　obtained　for　PBDTS-FBT　compared　to　PBDT-FBT.　On　the　other　side,　a　little　more　blueshifted　but　much　stronger　absorption　and　much　lower-lying　highest　occupied　molecular　orbital　(HOMO)　level　can　be　realized　for　PBDTF-FBT　when　introducing　fluorine　atoms　instead　of　sulfur　atoms.　With　the　combination　of　both　fluorination　and　sulfuration　strategies,　PBDTS-FBT　exhibits　the　best　absorption　ability,　lowest　HOMO　energy　level,　and　highest　crystallinity,　which　make　PBDTSF-FBT　devices　show　the　highest　power　conversion　efficiency　(PCE)　of　10.69%　in　fullerene　PSCs　and　11.66%　in　nonfullerene　PSCs.　The　PCE　of　11.66%　is　the　best　value　for　PSCs　based　on　BT-containing　copolymer　donors　reported　so　far.　The　results　indicate　that　fluorination　and　sulfuration　have　a　synergistically　positive　effect　on　the　performance　of　D-A　photovoltaic　copolymers　and　their　solar　cell　devices.