Objective:To explore the effect of the "organ system-based learning (OBL)" digestive system teaching model in the clinical internship teaching of undergraduate nursing students.Methods:A total of 84 nursing undergraduates who practiced in the digestive system department of a third-grade Class-A general hospital from July 2020 to May 2022 were selected as the research objects. According to the historical control study, they were divided into control group ( n=42) and experimental group ( n=42). The control group adopted traditional practice teaching, and the experimental group adopted OBL teaching. The admission theory scores of the two groups of nursing students in the department, graduation theory scores and technical scores, nursing students' core competency and clinical teaching satisfaction were compared. SPSS 24.0 was used for t-test and chi-square test. Results:There was no significant difference between the experimental group and the control group in admission theory scores. The graduation theory scores of the experimental group (93.27±1.47) and the control group (90.91±1.32) were statistically significant ( t=7.72, P<0.001). The graduation technical scores of the experimental group (94.51±1.81) and the control group (94.00±2.35) were not significantly different ( t=1.12, P=0.268). The core competency of nursing students in the experimental group (164.21±20.81) and the control group (152.79±15.76) was statistically significant ( t=2.84, P=0.006). Clinical teaching satisfaction of the experimental group (173.33±17.58) and the control group (152.67±19.74) was statistically significant ( t=5.07, P<0.001). Conclusion:The application of the OBL practice teaching model in the digestive system department is conducive to improving the theoretical knowledge of nursing students, and improving the core competence and clinical teaching satisfaction.