Objective To analyze the thermal damage of Staphylococcus aureus caused by diluent temperature by single factor variable experiment. Methods According to GB 4789.10-2016 Food safety national standard-Food microbiology inspection Staphylococcus aureus second method-Staphylococcus aureus plate counting method, Staphylococcus aureus was counted in different temperature diluents. Results The results of counting Staphylococcus aureus with dilution at 50 ℃ were lower. Conclusion The dilution at 50 ℃ can cause thermal damage to Staphylococcus aureus and affect the experimental results.