Objective To evaluate the measurement uncertainty in the determination of total plate count and coliform bacteria in cooked foods, thereby improving the accuracy of test results.Methods The plate counting methods specified in GB 4789.2—2022 and GB 4789.3—2025 were employed to detect 18 cooked food samples under two conditions (A and B). The combined standard uncertainty (u_c(y)) and expanded uncertainty (U=2×u_c(y)) were calculated in accordance with RB/T 228—2023.Results Based on intralaboratory reproducibility, the u_c(y) for total plate count determination was 0.030 3 (U=0.060 6), and that for coliform bacteria determination was 0.179 7 (U=0.359 7). When all uncertainty components were considered, the u_c(y) for total plate count determination of Sample 1 under Condition A increased to 0.109 4 (U=0.218 8), and that for coliform bacteria determination increased to 0.242 4 (U=0.484 8).Conclusion The primary factors affecting the measurement uncertainty of this method include technical uncertainty, matrix uncertainty, and distribution uncertainty. The application of RB/T 228—2023 for uncertainty assessment can improve the accuracy of test results.