OBJECTIVE: Numerous studies have shown that the mental health of middle school students is closely related to problematic mobile phone use. The purpose of this study is to investigate the network structure between the dimensions of the Middle School Students Mental Health Scale and the items of the Self-Rating Questionnaire for Adolescent Problematic Mobile Phone Use by using the network analysis, to clarify the core symptoms and bridge symptoms of the network structure, and to provide ideas and methods for intervening in the mental health and problematic mobile phone use of middle school students. METHODS: A stratified cluster sampling method was used to select 1637 students from four general middle schools in Xiamen in June 2020 for the survey, and the Middle School Students Mental Health Scale (MSSMHS-60) and the Self-Rating Questionnaire for Adolescent Problematic Mobile Phone Use (SQAPMPU) were used. SPSS28.0 was used for descriptive statistical analysis and R (version 4.2.1) for network analysis. RESULTS: 1. The core symptoms of the network of middle school students' mental health and problematic mobile phone use were "spending more time playing with the phone in order to be satisfied", anxiety, and depression; 2. The bridge symptoms of the network of middle school students' mental health and problematic mobile phone use were academic stress, psychological disequilibrium, and "depression without phone". CONCLUSION: Reducing the time of smartphone use and relieving anxiety and depression can improve the mental health of middle school students and reduce the incidence of problematic mobile phone use; helping middle school students adjust their study pressure and improving their social support level can reduce the severity of problematic mobile phone use.