Background  As a special group, soldiers are more likely to commit suicide. Non-suicidal self-injury (NSSI) is not only associated with clinical emergency department, the onset of dysfunction, but also a high-risk factor for suicide attempts. With the addition of diagnostic criteria of NSSI in the 5^th edition of The Diagnostic and Statistical Manual of Mental Disorder (DSM-5), NSSI has gradually become a hot topic in the field of psychiatry.

  Objective  To explore the relationship between NSSI behavior of soldiers and childhood maltreatment and the mediating effect of borderline personality on the association between childhood maltreatment and NSSI.

  Methods  From November 2021 to December 2021, a total of 1530 people, including 1500 males and 30 males with an average age of 25.96±5.150 years, were selected from a military unit. Childhood abuse experience, borderline personality trait and NSSI were measured by CTQ-SF, PDQ-4 + and SCID-5-CV, respectively.

  Results  There was a positive correlation between childhood maltreatment score and borderline personality score(r=0.239, P<0.01) and positively correlated with NSSI(r=0.123, P<0.01). Borderline personality score was also positively correlated with NSSI (r=0.167, P<0.01), borderline personality played a partial mediating role between childhood maltreatment and NSSI which the proportion of the mediation effect of total effect was 20.94%. In addition, among the factors of childhood maltreatment, borderline personality had a significant mediating effect on the association between emotional abuse, emotional neglect, physical abuse, physical neglect and NSSI, ranging from 13.70% to 37.56% of the total effect.

  Conclusion  NSSI behavior of soldiers is related to childhood maltreatment and borderline personality. Borderline personality has a partial mediating effect in the association between childhood maltreatment and NSSI, so the screening of borderline personality should be emphasized in conscription.