With　the　continuous　improvement　of　photovoltaic　efficiency　in　the　organic　photovoltaic　(OPV),　interface　engineering　has　emerged　as　a　pivotal　issue　in　their　practical　deployment.　Currently,　the　robust　crystallinity　of　small　molecule　electron　transport　layers　(ETLs)　and　the　poor　film-forming　abilities　of　conjugated　polymer　ETLs　are　a　huge　obstacle　in　this　field.　Herein,　an　innovative　and　efficient　non-conjugated　polymer　ETL,　namely　PNDI-SO,　which　contains　polar　cationic　segments　for　solubility　and　conjugated　units　for　efficient　charge　transport　in　stable　OPV　cells,　is　reported.　Endowed　with　suitable　energy　levels　and　excellent　electron　extraction　capabilities,　PNDI-SO-based　OPV　cells　attain　a　power　conversion　efficiency　(PCE)　of　18.54%.　Furthermore,　compared　with　conventional　OPV　cells　utilizing　PFN-Br　or　PDINN,　PNDI-SO　substantially　enhances　long-term　stability　under　continuous　illumination,　evidenced　by　a　T80　lifetime　(signifying　retention　of　80%　of　initial　performance)　exceeding　1250　h.　Notably,　through　scanning　electron　microscope,　we　verified　that　PNDI-SO　achieves　a　harmonious　balance　between　film-forming　ability　and　charge　transport　properties　for　ETL,　enabling　the　blade-coating　OPV　based　on　PBDB-TF:BTP-eC9　to　achieve　a　PCE　of　17.47%.　These　results　suggest　the　potential　of　PNDI-SO　as　a　promising　interface　material　for　industrial　printing　applications　in　OPV　fabrication.　©　2025