Objective: To explore the effectiveness of different intervention modalities on nonsuicidal selfinjury (NSSI) in adolescents, so as to provide an evidencebased basis for the intervention strategy of NSSI in adolescents. Methods: Randomized controlled trials on interventions for adolescent NSSI were retrieved from databases, such as CNKI, Wanfang, VIP, CBM, Web of Science, PubMed, Embase, and Cochrane Library, spanning from the inception of these databases to March 5, 2025. Network Metaanalysis was performed by using Stata 17.0 and Review Manager 5.3 software, and the standardized mean difference (SMD) and 95%CI were used as the effect indicators to compare the differences in the effectiveness of the interventions and rank the effect. Results: A total of 26 articles with 2 034 adolescents with NSSI were included in the study, including 10 intervention modalities:dialectical behavior therapy, emotional regulation intervention, mentalizationbased therapy, family therapy, cutting down programme, cognitive behavioral therapy, narrative therapy, stepped care approach, positive psychological intervention, and acceptance and commitment therapy. The results showed that compared with the treatment as usual, positive psychological intervention [SMD(95%CI)=-2.12(-3.51 to -0.74)], stepped care intervention [SMD(95%CI)=-2.07(-3.43 to -0.71)], and dialectical behavior therapy [SMD(95%CI)=-1.70(-2.60 to -0.80)], cognitive behavioral therapy [SMD(95%CI)=-1.54(-2.61 to -0.48)], and acceptance and commitment therapy[SMD(95%CI)=-1.50(-2.68 to -0.32)] were statistically significant differences in reducing adolescents NSSI behaviors(P<0.05). Positive psychological intervention, stepped care intervention, and dialectical behavior therapy were more effective than the mentalizationbased therapy and the cutting down programme (SMD=-2.08, -2.03, -1.66, -2.06, -2.01, -1.64,P<0.05); the area under the cumulative ranking probability graph revealed that positive psychological intervention may have the best effect in improving NSSI among adolescents (82.5). Conclusions Positive psychological interventions show the best results in improving adolescent NSSI among multiple intervention modalities. It is recommended to give priority to positive psychological interventions in clinical interventions.