<p>This study examined the effects of interparental conflict on non-suicidal self-injury in middle school students and investigated the mediating role of self-esteem and the moderating role of regulatory emotional self-efficacy. A total of 1,072 middle school students were recruited to participate in this study and anonymously completed the Children’s Perception of Interparental Conflict Scale, Self-esteem Scale, Regulatory Emotional Self-efficacy Scale, and Adolescent Self-Injury Questionnaire. The results were as follows: (1) Interparental conflict positively predicted non-suicidal self-injury in middle school students; (2) self-esteem mediated the relationship between interparental conflict and non-suicidal self-injury; (3) the relationship between self-esteem and non-suicidal self-injury was moderated by regulatory emotional self-efficacy. These findings provide a new avenue for reducing and preventing non-suicidal self-injury among middle school students.</p>