Online game addiction has become a very serious social problem nowadays, and for adolescents at the stage of ego-identity construction, game addiction has great harm to them. Especially with the emergence of mobile online games, the convenience of using them anytime and anywhere and the sense of smooth flow experience make people deeply addicted to online games, and the avatars of adolescent players who are addicted to games will affect their real individual self-identity and make them feel anxiety and emptiness of the mismatch between virtual and real personalities. Based on the theories of adolescent ego-identity, this study explores the specific influence paths and deep-seated mechanisms of online game addiction from the perspectives of avatar identification and game flow experience. 746 Chinese adolescent gamers aged 11 to 18 years old completed an online questionnaire survey. The results showed that adolescent ego-identity negatively predicted online game addiction, and adolescents with more positive ego-identity evaluations were less likely to develop online game addiction; adolescent ego-identity also had a significant negative predictive effect on avatar identification, and avatar identification had a mediating role in the overall model; adolescent ego-identity could be mediated not only by avatar identification alone, but also by the sequential mediating effect of avatar identification and The present study focused on the psychological effects of adolescent ego-identity on online game addiction. This study focuses on examining the psychological characteristics of adolescent individuals, which provides a new perspective and a new research model for subsequent research on online game addiction, while this study examines the serial mediation effect of avatar identification and flow experience sense, which verifies the important role of avatar identification and flow experience in the process of adolescent online game addiction, and subsequent studies can enrich new variables on this basis to further explore the relationship between adolescent personal traits and psychological behaviors and online game addiction.