To investigate the mediating role of rumination in the association between childhood maltreatment and suicidal behavior, and the moderating role of regulatory emotional self-efficacy, university students (N = 1,458) from 5 universities in China completed questionnaires in classrooms. Path analyses showed emotional maltreatment had the greatest positive association with suicidal behavior and rumination compared with other types of childhood maltreatment. Rumination partly mediated the relationship between childhood maltreatment and suicidal behavior. High regulatory emotional self-efficacy moderated the relation between ruminating childhood maltreatment and suicidal behavior.