Objective: To evaluate the uncertainty of the determination of thiocyanate in cheese by inhibition conductance ion chromatography. Methods: The content of thiocyanate in cheese was determined by inhibition conductance ion chromatography and a mathematical model was established. The source of uncertainty introduced in the process of the experiment was described, and the synthetic uncertainty was calculated for each uncertainty component. Results: The determination of thiocyanate was （10.2±0.56） mg/kg, k=2, p=95%. Conclusion: The uncertainty in the measurement process mainly comes from the concentration of thiocyanate in the test solution, followed by sample recovery and repeatability experiments.