<p>Mulberry is crucial in silkworm rearing as it provides the primary food source for silkworms, directly impacting the quality and quantity of silk production. This, in turn, supports the global silk industry, which significantly contributes to the economies of many countries through the production of textiles and garments. Postharvest mulberry leaf preservation is required to ensure a continuous and reliable food supply for silkworms, especially during the rainy season when fresh dry leaves are not readily available. Proper preservation techniques will ensure the leaves' nutritional quality, which is essential for the health and productivity of silkworms, ultimately enhancing the efficiency and profitability of silk production. Due to their potent antimicrobial properties, silver-doped copper oxide nanoparticles (Ag-CuO NPs) are explored as preservatives. When used for preservation, Ag-CuO NPs effectively retained primary metabolites, chlorophyll, proteins, and carbohydrates, preserving the leaves' texture and nutritional value. Additionally, the synergistic action of enzymatic antioxidants and carotenoids with Ag-CuO NPs mitigated reactive oxygen species (ROS) damage, delayed senescence, and maintained cellular integrity. Postharvest leaves treated with Ag-CuO NPs supported optimal silkworm larval growth, resulting in higher growth indices, cocoon weights, and silk yields, comparable to fresh leaves. This nanoparticle-based approach extends leaf viability up to seven days, offering a sustainable and non-toxic preservation method with reduced environmental impact, enhancing the efficiency of sericulture practices.</p>