Objective: To explore the application effect of a guided self help intervention based on dialectical behavior therapy (DBT) to address non suicidal self injury (NSSI) behavior among college students, so as to provide a reference for reducing the occurrence of NSSI behavior in this population. Methods: A total of 106 college students with NSSI admitted to the Department of Child and Adolescent Psychology, the Second Affiliated Hospital of Jining Medical University from January 2021 to January 2023 were selected and divided into an observation group and a control group, with 53 cases in each group, using a random number table method. The control group received routine medication treatment and psychological intervention, while the observation group, on the basis of the interventions provided to the control group, implemented dialectical behavior therapy based guided self help. The approach combines group activities, individual counseling, and selfdirected learning, covering four core modules: mindfulness training, distress tolerance, interpersonal effectiveness, and emotion regulation. Meanwhile, data collection, skill check ins, and personalized recommendation pushes were conducted through a WeChat. Both groups were intervented for 12 weeks. Before the intervention and after the intervention, the Adolescent Non suicidal Self injury Behavior Questionnaire, Ottawa Self injury Inventory (OSI), and Barratt Impulsiveness Scale (BIS) were used to evaluate the patients, and the levels of serum neurotransmitters were detected. The χ 2 test, t test, and Cochran s Q test were used for data comparison and analysis. Results: The incidence rates of NSSI in the observation group after 3, 6, and 12 weeks of intervention were 47.17%, 16.98%, and 5.66%, respectively, all lower than those in the control group (67.92%, 35.85%, 20.75%) ( χ 2=4.67, 4.85, 5.27,all P <0.05). After 12 weeks of intervention, in the NSSI Behavior Questionnaire, the total score of the observation group was (17.94±2.69) points, which was lower than that of the control group (23.04±5.11) points; in the Function Questionnaire, the total score of the observation group was (53.24±8.94) points, which was higher than that of the control group (47.74±8.00) points（both P ＜0.05）. In terms of the OSI, the total score of the observation group was (4.49±0.62) points, lower than that of the control group (6.25±0.81) points;in the BIS, the total score of the observation group was (80.76±7.94) points, lower than that of the control group (87.74±9.34) points，and the differences between groups were statistically significant(both P<0.05). After the intervention, the level of 5-hydroxytryptamine in the observation group was (67.93±5.42) ng/mL, higher than (44.72±5.54) ng/mL of the control group; the levels of substance P and cortisol in the observation group were (35.82±4.47) ng/L and (75.64±8.02) μg/L, respectively, both lower than (48.14±5.32) ng/L and (94.53±10.78) μg/L of the control group, and the differences were statistically significant (all P <0.05). Conclusion The guided self help intervention based on DBT is helpful for reducing NSSI behavior among college students.