Objective: To explore the effect of behavioral activation (BA) therapy on depressive mood and behavioral characteristics among subliminal depressed nursing students, and to provide a reference for effective mental health education to nursing students. Methods: A cluster sampling method was used to select 614 sophomore nursing students from a medical college in Jiangxi Province. Sixty subjects who met the inclusion criteria were enrolled in the study, and divided into a control group and an intervention group using a random number table method, with 30 participants in each group. The control group received general mental health education, and the intervention group participated in a BA intervention on the basis of general mental health education. The Center for Epidemiologic Studies Depression (CES-D), Beck Depression Inventory II(BDI-II) and the Behavioral Activation For Depression Scale Short Form (BADS-SF) were used to evaluate students depression status before, immediately after, and 1 month after the intervention, respectively. Results: The time effect, group effect, and time group interaction of the CES-D, BDI-II and BADS-SF scores of the two groups of students were all statistically significant ( F =82.78, 9.65, 69.92; 42.19, 10.52, 13.50; 15.59 , 19.61, 8.49, P <0.01). Immediately after the intervention and 1 month after the intervention, the CES-D and BDI-II scores of the intervention group were significantly lower than those of the control group, and the BADS-SF score of the intervention group (14.63±4.63, 14.80±4.85; 11.23±4.98, 11.13±5.53) was significantly lower than that of the control group (22.67±6.70, 22.13±5.66; 17.57±9.59, 18.37±7.91); the differences were all statistically significant ( P <0.05). Conclusion BA shows lasting effects on alleviating depressive symptoms among nursing students with subthreshold depression, improve their behavioral activation level, and have a lasting effect. Nursing educators can improve the depression of nursing students and improve their mental health through individual BA.