<p>Conductive polymers have recently drawn tremendous attention due to their promising applications in electronic and energy-related devices. While p-type conductive polymers such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) have achieved commercialization, the development of stable, high-performance n-type polymers has lagged. Recently, the discovery of n-type polymer poly(benzodifurandione) (PBFDO) has greatly promoted the development and application of n-type conductive polymers. However, the synthesis process involves cumbersome post-processing, which greatly increases the cost and difficulty of mass production. Herein, a novel synthesis method for PBFDO has been developed, which was promoted by the combination of solvent dimethyl sulfoxide (DMSO) and acetic anhydride (Ac₂O). This method exploits the oxidative capability of DMSO, activated by Ac₂O, which can promote the keto-enol tautomerism of 3,7-dihydrobenzo[1,2-b:4,5-b’]difuran-2,6-dione (BFDO) and induce the rapid polymerization. The resulting PBFDO ink exhibits a high electronic conductivity of more than 2000 S cm^-1 and excellent ambient stability. Significantly, the additives and by-products remain in a liquid state during the polymerization process and possess low boiling points, allowing for the production of pure PBFDO films through straightforward heating and drying. Furthermore, this approach holds considerable promise for <i>in situ</i> polymerization, as functional conductive films can be prepared by merely combining the monomers with the DMSO/Ac₂O mixture and applying heat. This efficient, purification-free strategy represents a significant step toward the industrial application of the high-performance n-type conductive polymer PBFDO.</p>