To better assess the indicators of Staphylococcus aureus in foods.Methods According to JJF 1059.1-2012, the uncertainty of plate counting measurement of Staphylococcus aureus in foods was evaluated. Results The expanded uncertainty of measurement was U=0.072×lgT(T-the colony count of Staphylococcus aureus in foods), k=2.Conclusion The uncertainty evaluation of measurement can accurately evaluate the food and ensure the safety of the food from factory.