The power conversion efficiency (PCE) of polymer solar cells (PSCs) has exceeded 19% due to the rapid progress of photoactive organic materials, including conjugated polymer donors and the matched non-fullerene acceptors (NFAs). Due to the high density of oxygen vacancies and the consequent photocatalytic reactivity of ZnO, structure inverted polymer solar cells with the ZnO electron transport layer (ETL) usually suffer poor device photostability. In this work, the eco-friendly glucose (Glu) is found to simultaneously improve the efficiency and stability of polymer:NFA solar cells. Under the optimal conditions, we achieved improved PCEs from 14.77% to 15.86% for the PM6:Y6 solar cells. Such a PCE improvement was attributed to the improvement in JSC and FF, which is ascribed to the smoother and more hydrophobic surface of the ZnO/Glu surface, thereby enhancing the charge extraction efficiency and inhibiting charge recombination. Besides, UV-Vis absorption spectra analysis revealed that glucose modification could significantly inhibit the photodegradation of Y6, resulting in a significant improvement in the stability of the device with 92% of its initial PCE after aging for 1250 h. The application of natural interface materials in this work brings hope for the commercial application of organic solar cells and provides new ideas for developing new interface materials. [ABSTRACT FROM AUTHOR]