Incidence of NSSI rises during adolescence and peaks in young adulthood. Secondary school and university students, representing these age groups, have been the focus of research on how emotion regulation strategies impact NSSI. However, a comprehensive study of the interrelations among different symptoms is needed. Research based on network analysis, a questionnaire survey on emotion regulation strategies and NSSI was conducted with 378 secondary school students and 593 first-year university students, all of whom reported a history of engagement in NSSI. The results indicated that Cognitive reappraisal symptoms showed a positive or no correlation with NSSI, while expressive suppression symptoms demonstrated a negative or no correlation. Secondary school and university students using cognitive reappraisal or expressive suppression also tended to use the other type of emotion regulation strategy simultaneously. In secondary school NSSI groups, core symptoms were linked to cognitive reappraisal, while in university groups, they were linked to expressive suppression. Intervention targets for NSSI in secondary school students included “I keep my emotions to myself”, and for university students, “I control my emotions by not expressing them.” Research reveals a complex mechanism underlying the link between NSSI and emotion regulation strategies in university and secondary school students, offering valuable insights for promoting the psychological health of adolescents and youths.

Suicidal ideation tends to be hidden, limiting the ability of current assessment tools to reliably identify at-risk individuals. Based on the spreading act