Objective: To explore the association between adolescent peer bullying, life satisfaction and self-harm, so as to provide intervention support for the prevention of adolescent self-harm behaviors. Methods: In October 2022, 5 724 junior high school students from Xuancheng, Hefei, Huaibei in Anhui Province were selected by multistage stratified random cluster sampling, and a self-administered adolescent mental health behavior questionnaire was used to conduct the survey. Results: The detection rate of peer bullying among adolescents was 30.0%, and the detection rates of the five self-harm behaviors including highly lethal self-harm, less lethal self-harm with visible tissue damage, self-harm without visible tissue damage, self-harm with latency damage, and psychological self-harm were 10.2%, 25.8%, 35.5%, 20.8% and 28.2%, respectively. Logistic regression model results showed a positive association between exposure to peer bullying and the five self-harmful behaviors ( OR =2.52-3.21, P <0.01), and a negative association between life satisfaction and the five self-harmful behaviors ( OR =0.19-0.33, P <0.01). Adolescent life satisfaction had a moderating effect between exposure to peer bullying and highly lethal self-harm, less lethal self-harm with visible tissue damage, self-harm without visible tissue damage, and self-harm with latency damage ( OR=1.53, 1.42, 1.30, 1.39, P <0.05), and no moderating effect between exposure to peer bullying and psychological self-harm ( P >0.05). Conclusion Peer bullying among adolescents may increase the risk of self-harm behavior. Improvement of life satisfaction can effectively mitigate the negative effects of peer bullying on adolescent self-harm.