Objective To explore the influence of radiation protection knowledge-attitude-practice (RP-KAP) on occupational stress of radiation workers. Methods A total of 314 radiation workers from five hospitals in Shijiazhuang City were selected as the study subjects using the convenient sampling method. The Chinese version of the "Effort-Reward Imbalance (ERI) Questionnaire" and the "Radiation Protection Knowledge, Attitude, and Practice Questionnaire" were used for investigation. Results The detection rate of occupational stress in ERI model among the radiation workers was 74.5% (234/314). The RP-KAP practice dimension score of the population in the occupational stress group was lower than that in the non-occupational stress group (P<0.05). The results of binary logistic regression analysis showed that radiation workers with lower RP-KAP practice dimension score had a higher risk of occupational stress (P<0.01), and the risks of occupational stress among population of interventional radiology group and radiotherapy group were higher than that of X-ray diagnosis group and nuclear medicine group (both P<0.05), after controlling for confounding factors such as gender, age, type of work, professional title, daily working hours, weekly working hours and regular vacation. Conclusion RP-KAP is the influencing factor of occupational stress in the radiation workers. To improve the radiation workers' knowledge of radiation protection, protection awareness and compliance with protective behavior can effectively reduce or even eliminate occupational stress.