Objective To improve the measurement accuracy of cesium-137 (Cs-137) content in food using low-background α/β measuring instruments.Methods An uncertainty analysis model for measuring Cs-137 in food was established based on the second method in GB 14883.10-2016. The uncertainty components affecting the detection process were analyzed, the sources of uncertainty were explored, and the uncertainty was evaluated.Results Through uncertainty analysis introduced by sample measurement, supervised source measurement, cesium recovery rate calibration, sample sampling, sample ash-to-fresh ratio, standard source calibration supervised source, and self-absorption coefficient calibration, the activity concentration of Cs-137 in food determined by the ammonium phosphomolybdate method was 1.44 Bq/kg, with an expanded uncertainty of 0.13 Bq/kg (k=2).Conclusion The main factor affecting the uncertainty of Cs-137 measurement in food by low-background α/β measuring instruments is the uncertainty introduced during the sample measurement process, followed by the uncertainty introduced by the standard source calibration supervision source.