A new polymer acceptor, PS1, was developed by connecting the non-fullerene acceptor building block of dithienothiophen[3,2-b]pyrrolobenzotriazole capped with 3-(dicyanomethylidene)-indan-1-one through a thiophene spacer. The solubilizing alkyl side groups in the central unit enabled PS1 to be readily dissolved in non-chlorinated solvents. By using 2-methyltetrahydrofuran as the processing solvent, the all-polymer solar cell (all-PSC) containing PS1 and a polymer donor PTzBI-oF in the light-harvesting layer exhibited an impressively high power conversion efficiency of 13.8%.