The fruit of Akebia trifoliata var. australis can be consumed as food. However, the peel of this fruit is typically regarded as waste. The application of such waste can create opportunities to produce new and valuable by-products. Herein, we have shown that citric acid extracted pectin (CEP) from Akebia trifoliata var. australis peel has good water solubility and high galacturonic units, which helps reduce AgNO₃ into Ag nanoparticles (CEP-AgNPs) through a one-step, eco-friendly process. The resulting CEP-AgNPs showed sustained release of Ag⁺ and remarkable antibacterial activity. Subsequently, the CEP-AgNPs were processed into a CEP-Ag sponge with excellent water absorption and prolonged water retention properties. The CEP-Ag sponge could support the cell adhesion and proliferation. Most importantly, the sponge effectively facilitated a moist environment with bacterial disinfection capability which accelerated the healing of infected wounds. Thus, CEP-Ag sponge, a sustainable and high value by-product, was obtained from food waste.