A　polymerized　small-molecule　acceptor,　NC-PY6,　has　been　newly　designed　and　successfully　synthesized.　NC-PY6　contains　a　rigid　conjugated　Y6-derived　fused-ring　small　acceptor　SY6　and　a　non-conjugated　alkyl　chain　as　the　linkage.　Similar　to　SY6,　NC-PY6　exhibits　the　narrow　bandgap　of　1.44　eV　and　the　low-lying　lowest　unoccupied　molecular　orbital　energy　level　(-3.92　eV),　which　match　with　the　known　wide-bandgap　polymer　donor　D18.　The　D18:SY6　based　polymer　solar　cells　showed　a　power　conversion　efficiency　(PCE)　of　13.1%　with　a　voltage　loss　of　0.58　V.　The　all-polymer　solar　cells　(all-PSCs)　based　on　D18:NC-PY6　blend　film　gave　an　encouraging　PCE　of　12.3%　with　a　voltage　loss　of　0.57　V.　The　results　demonstrate　the　potential　of　molecular　design　strategy　of　polymerizing　small-molecule　acceptor　with　the　non-conjugated　alkyl　chain　as　the　linkage　for　new　type　of　polymer　acceptors　for　high-performance　all-PSCs.