Abstract: Potatoes are susceptible to light-induced greening during storage, which seriously affects their quality and commodity value. The purpose of this study was to explore the inhibitory effect of sodium copper chlorophyllin coating on postharvest potato greening. Potato tubers were treated with sodium copper chlorophyllin coating, and their a^* value, chlorophyll content and respiration rate were measured regularly, which the effects of coating on greening were evaluated. Non-target metabolomics was employed to analyze metabolite changes, and the metabolic mechanism of inhibition of green change was analyzed. The results showed that after 60 days of storage, compared with untreated potato tubers, the potato tubers treated with composite coating exhibited a 28.60% increase in a^* value, while chlorophyll content and respiration rate decreased, indicating that the composite coating treatment could effectively slow down the greening process of potato tubers. Metabolomics analysis revealed that the sodium copper chlorophyllin coating effectively suppressed respiratory intensity by reducing the levels of key respiratory substrates such as pyruvate and citrate within these pathways. The coating also reduced chlorophyll content by inhibiting the biosynthesis process of key precursors for chlorophyll synthesis, such as glutamine and glutamic acid. This study validated the effectiveness of sodium copper chlorophyllin coating in preventing postharvest greening of potatoes, providing a new technical approach for improving potato quality.