〔Abstract〕 Objective To explore the application of standardized case guided teaching mode in clinical teaching of tumor radiotherapy department. Methods 100 undergraduate interns of clinical medicine who practiced in the Department of tumor Radiotherapy in The First Affiliated Hospital of Anhui Medical University from July 2021 to July 2022 were selected as the research objects and randomly divided into an observation group and a control group, with 50 persons in each group. The interns in the control group were taught in the traditional conventional mode, and the interns in the observation group were taught in the standardized case-guided teaching mode. The assessment results, the degree of recognition of the teaching method, the degree of satisfaction with the teaching and the satisfaction of patients were observed and recorded. Results After teaching, the theoretical examination, case analysis, emergency treatment, operation skills and total scores of interns in the observation group were higher than those in the control group, the differences were statistically significant (P < 0.05). Interns in the observation group were higher than those in the control group in interpersonal communication and teamwork ability, judgment and thinking ability, knowledge expansion, self-learning ability, clear learning goals, and comprehensive mastery of theoretical and operational knowledge, the differences were statistically significant (P < 0.05). The total satisfaction of interns in the observation group (98.00 %) was higher than that in the control group (60.00 %), and the difference was statistically significant (P < 0.05). The patient satisfaction of interns in the observation group (96.00 %) was higher than that in the control group (70.00 %), and the difference was statistically significant (P < 0.05). Conclusion The application of standardized case-guided teaching mode in clinical teaching of oncology radiotherapy department can significantly improve the theoretical knowledge level and clinical practice ability of clinical interns, which is widely recognized by the interns.