BACKGROUND: In the information age, the use of the internet and multimedia tools has large effects on the life of middle school students. Improper use of the internet may result in internet addiction (IA). Thus, actively exploring the factors influencing adolescent and the mechanism of addiction as well as promoting adolescent physical and mental health and academic development are priorities that families, schools, and society urgently need to address. AIM: To explore the effect of childhood trauma on adolescent IA and to consider the roles of loneliness and negative coping styles. METHODS: A total of 11310 students from six junior high schools in Henan, China, completed the child trauma questionnaire, IA test, loneliness scale, and simple coping style questionnaire. In addition, data were collected from 1044 adolescents with childhood trauma for analysis with IBM SPSS 26.0 and AMOS 28.0; we examined the relationships among childhood trauma, IA, loneliness, and negative coping styles. RESULTS: We found that childhood trauma not only directly affected adolescents' IA but also affected IA through loneliness and negative coping styles. CONCLUSION: Therefore, this study has theoretical implications regarding adolescent mental health and may inform interventions for IA.