Objective To investigate the association between low-level ionizing radiation exposure and peripheral blood parameters in medical radiation workers, and to provide evidence for radiation protection strategies and occupational health surveillance. Methods A total of 1261 medical radiation workers from medical institutions in Heze City, Shandong Province, China, were enrolled. Individual monitoring of occupational external exposure was performed. Demographic characteristics and physical examination data were collected. According to the median annual effective dose, the subjects were stratified into a low-dose group (0.10-0.43 mSv) and a high-dose group (>0.43-5.24 mSv). Logistic regression was used to assess the association between ionizing radiation and peripheral blood parameters. Subgroup analyses were conducted by gender, age, and exposure duration. Results A total of 1261 subjects were enrolled, of whom 893 (70.82%) were male and 368 (29.18%) were female. The median age was 39.00 (32.00, 47.00) years and the median exposure duration was 11.00 (5.00, 22.00) years. No statistically significant differences in baseline characteristics were observed between the two groups. The radiation dose ranged from 0.104 to 5.239 mSv, all below the occupational exposure limit (20 mSv). Basophil count, hematocrit, and mean corpuscular volume in the high-dose group were significantly higher than those in the low-dose group, while mean corpuscular hemoglobin concentration was lower (P<0.05). Logistic regression analysis showed that ionizing radiation primarily affected erythrocyte parameters, with abnormal hematocrit (OR=1.449, 95%CI: 1.148-1.831), abnormal mean corpuscular volume (OR=1.407, 95%CI: 1.119-1.771), and abnormal mean corpuscular hemoglobin concentration (OR=1.608, 95%CI: 1.278-2.025) positively associated with ionizing radiation exposure. Subgroup analyses further revealed differences that were not observed in the total population These findings suggest that gender, age, and exposure duration may modify the effect of ionizing radiation on peripheral blood parameters. Conclusion Long-term low-level ionizing radiation exposure can affect peripheral blood parameters in medical radiation workers, particularly erythrocyte parameters. Enhanced occupational health monitoring and protection measures are warranted.