Objective: To understand mental health status of middle school students in Weifang, and to analyze its association with health risk behaviors, and to provide a reference basis for the effective prevention of mental health problems. Methods: Using the self-designed questionnaire and Kessler l0 (K10), a total of 3 185 middle school students in Weifang selected by using stratified clustered sampling were investigated. Chi-square test and binary Logistic regression was used for statistical analysis. Results: Among the middle school students in Weifang, 1 634(51.3%) reported good mental health, 854(26.8%) in moderate level, 394(12.4%) reported poor mental health, and 303(9.5%) reported very poor mental health. Sleep duration and smoking were associated with mental health of middle school students (P<0.05). Logistic regression analyses showed that, compared with adolescents with sleep duration less than 8 h, mental health among students whose sleep duration ≥8 h was better(OR=0.36); compared with non-smokers, students who smoked showed worse mental health status (OR=3.53). Conclusion Health-risk behaviors are closely related to mental health of middle school students. Relevant departments should strengthen education and publicity of healthy lifestyles, and pay close attention to the impact of health risk behaviors on mental health.