Reuse of electrode substrate is one of the most important schemes to reduce the cost and thus promote the application of polymer solar cells. The present paper developed a procedure for cleaning the surface of indium tin oxide (ITO) from abandoned polymer solar cells, and studied the effects of recycled ITO on the performance of PBDB-T-2F:IT-4F and PTB7:PC71BM solar cells. The results showed that the active layer, interface layers and top electrode can be completely cleaned from ITO substrate by treating in chloroform and weak acid solutions. Moreover, it was found that the recycled ITO can be applied in the fabrication of new polymer solar cells again, and a higher power conversion efficiency (13.21%) of PBDB-T-2F:IT-4F solar cell based on recycled ITO, compared to that based on original ITO (12.86%), has been demonstrated. The enhanced performance of solar cell mainly originated from the reduced carrier recombination of photogenerated charges by optimizing the morphology of recycled ITO. Therefore, this work demonstrated the feasibility of the development of low-cost and high-efficiency polymer solar cells via recycled ITO substrate. Graphic abstract