Objective To explore the correlation between personality traits and non suicidal self injury behavior in adolescent depression patients， in order to enhance understanding of the psychological health risks of depression patients. Methods This study was conducted at the Wuhan Mental Health Center from September 2021 to September 2023. A total of 138 patients with first-onset moderate to severe adolescent depression were included. The patients were divided into a group without self injury suicidal behavior （n = 25）， a non suicidal self injury （NSSI） group （n = 78）， and an attempted suicide （SA） group （n = 35）. Collect general information and data on neurotic personality scores， negative life events， emotional states， and social psychological factors using the Hamilton Anxiety Scale （HAMA）， Hamilton Depression Scale （HAMD-24）， and other psychological assessment tools. Using statistical methods for correlation and regression analysis to study the relationship between personality traits and non suicidal self injury behavior. Results There were significant differences in personality traits such as internal and external tendencies， psychoticism， neuroticism， and concealment among the non self injurious suicide behavior group， non suicidal self injurious behavior group， and suicide behavior group. The scores of the non suicidal self injurious behavior group and suicide behavior group were generally higher than those of the non self injurious self injurious behavior group （P < 0.05）； There were significant differences in self injury behavior scores among these three groups， especially in the suicide behavior group， which had the highest score， but there was no significant difference in life event scores； There were significant differences in scores for anxiety， depression， childhood trauma， stressful life events， and self-esteem among the three groups. Among them， the suicide behavior group had the highest scores for anxiety， depression， childhood trauma， and stressful life events， but the lowest score for self-esteem （P < 0.05）； Internal and external tendencies， psychoticism， neuroticism， and concealment are significantly correlated with non suicidal self injury behavior， and multiple regression analysis results show that these factors， as well as anxiety， depression， childhood trauma， stressful life events， and self-esteem， are independent influencing factors of non suicidal self injury behavior. The best predictive threshold for internal and external tendencies is -10.5%. Conclusion This study reveals the correlation between personality traits and non suicidal self injury behavior in adolescent depression patients. Understanding these relationships in clinical practice and intervention strategies can help better identify high-risk groups and provide personalized mental health support.