Objective: To explore the interactive mechanisms of middle school students lifestyle with depressive and anxiety symptoms, so as to provide a basis for constructing a precise prevention system of middle school students mental health. Methods: From October to December in 2024, a stratified cluster random sampling method was used to select 6 251 middle school students from Guangxi. The Lifestyle Questionnaire, Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 ( GAD- 7) were used to investigate middle school students lifestyle, depressive symptoms and anxiety symptoms. The relationship of adolescent lifestyle with depressive and anxiety symptoms was analyzed through binary Logistic regression. The network analysis method was used to construct the network of middle school students lifestyle with depressive and anxiety symptoms. Results: A total of 1 690 individuals (27.0%) exhibited depressive symptoms, and 1 071 individuals (17.1%) exhibited anxiety symptoms. Binary Logistic regression analysis revealed that smoking, alcohol consumption, excessive intake of sugary drinks, insufficient vegetable intake, not eating breakfast daily, frequent consumption of fast food, prolonged sedentary time on both weekdays and weekends, insufficient sleep duration on weekdays and weekends, and excessive screen time on weekdays were all associated with depressive symptom ( OR =1.19-2.07) and anxiety symptom ( OR =1.20-1.91) in middle school students(all P ＜0.05). Additionally, excessive screen time on weekends was associated only with depressive symptoms ( OR =1.35, P <0.05). The connection between the lifestyle-depressive symptom cluster was mainly through "breakfast" and "suicidal ideation" (weight=0.31); the connection between the lifestyle-anxiety symptom cluster was mainly through "sedentary time on weekdays" and "uncontrollable worry" (weight=0.34). In the depressive symptom network, "depressed mood" had the highest node strength; in the anxiety symptom network, "uncontrollable worry" had the highest node strength. "Suicidal ideation" was a key bridge node between lifestyle and depressive and anxiety symptoms. Conclusions Unhealthy lifestyles are significant modifiable risk factors for depressive and anxiety symptoms among middle school students. Regular breakfast intake and management of sedentary behavior should be prioritized as important intervention entry points.