Potassium sorbate (PS) is a widely utilized food preservative with bactericidal solid effects. However, it can cause serious side effects and health risks when the dosage is exceeded.Thus, developing an exceptional probe for detecting trace amounts of PS was significantly important. Bimetallic nanoclusters, compared to monometallic nanoclusters, possess better chemical performance. Herein, we introduce a novel fluorescence of Ag/CuNCs (at excitation/emission peaks of 395/680 nm)as a fluorescent probe, is quenched by PS due to electron-transfer (PET) between Ag/CuNCs and PS. the present sensor system exhibits a good linear response to PS ranging from 0.08 to 45 μM, and the limit of detection was found to be 3.7 nM. Its applicability has also been confirmed successfully in drinks. Due to its high stability, sensitivity, and selectivity, this bimetallic cluster-based sensing system shows great promise for application in food safety testing.