Objective To explore the effect of applying immersive game-based teaching of diet care to nursing students working in the department of gastroenterology. Methods Totally,80 nursing students having internship in 2 affiliated hospitals were randomized into 2 groups of 40 students each.The control group was subjected to conventional diet care teaching, while the intervention group to immersive game-based teaching:students served as game players, and had to pass through checkpoints to learn knowledge and skills in diet care.On the day of unit check-in and check-out, the nursing students were assessed for diet care competence and critical thinking ability. Results After intervention, the intervention group had higher diet care competence scores, as well as critical thinking ability totals and dimension scores, than the control group （P＜0.05，P＜0.01）. Conclusion Application of immersive game-based teaching of diet care in department of gastroenterology, can effectively improve nursing students′ diet care competence and critical thinking ability.