Objective To evaluate the levels and changes in occupational individual external radiation dose in non-medical nuclear utilization units in Nanning City, and to provide a basis for radiation protection in such units. Methods Thermoluminescent dosimeters were used to monitor individual radiation doses among radiation workers in 38 non-medical nuclear utilization units in Nanning City. The results were subjected to statistical analysis. Results From 2021 to 2023, a total of 3724 person-times were monitored in 38 non-medical nuclear utilization units in Nanning City. The mean annual effective dose was 0.101 mSv in 2021, 0.060 mSv in 2022, and 0.094 mSv in 2023, with a three-year average of 0.085 mSv, all well below the occupational exposure limit of 1.0 mSv. Significant differences in mean annual effective doses were observed across occupations and sexes (P<0.05). Female workers received significantly lower mean annual effective dose than male workers. Workers in the cement manufacturing industry had a significantly higher mean annual effective dose compared to those in government institutions and industrial flaw detection practitioners (F = 2.913, P<0.05). No significant differences were found among workers exposed to unsealed radioactive sources, sealed radioactive sources, and radiation-generating equipment (F = 0.585, P>0.05). Conclusion The occupational individual external radiation doses in non-medical nuclear utilization units in Nanning City are at low levels. There are no significant differences in mean annual effective dose across different nuclear utilization units. However, differences in occupational roles between males and females significantly affect the mean annual effective dose.