Objective To evaluate the intervention effect of emotional regulation strategy on non-suicidal self-injury (NSSI) behavior of adolescents with depressive disorder. Methods A total of 90 adolescents with depressive disorder and a history of NSSI were divided into a control group and an intervention group using a random number table, with 45 cases in each group. The control group received routine safety assessment and management, while the intervention group received short-term hospitalization intervention dominated by emotional regulation strategy in the form of face to face sessions, twice a week, 1 hour each session, streching 7 times. Results Three months after the intervention, the frequency of NSSI and the most serious physical injury in the intervention group were significantly lower than those in the control group, the scores of adaptive cognitive emotional regulation strategy were significantly higher than those in the control group, while the scores of non-adaptive cognitive emotional regulation strategy were significantly lower than those in the control group (P<0.01 for all). Conclusion The short-term hospitalization intervention dominated by emotional regulation strategy is beneficial to improve the cognitive and emotional regulation ability of adolescents with depressive disorder, and reduce their NSSI behavior.