BACKGROUND: Mobile phone dependence is a common problem in the population of high school students. We aimed to evaluate the core self-evaluation, mental health and mobile phone dependence in Chinese high school students, to provide reliable evidence to the support of high school students. METHODS: We conducted a survey of high school students in Xiamen, China. The self-assessment questionnaire on mobile phone use dependence among teenagers (SQAPMPU), Mental Health Scale for Middle School Students (MSSMHS) and Core self-evaluation scale were used to evaluate the mobile phone dependence, mental health and core self-evaluation. t-tests, Pearson correlation and multiple linear stepwise regression analyses were conducted to analyze the potential relationships. RESULTS: A total of 1692 students were enrolled. The total score of mobile phone dependence of students in grades 10-12 was higher than that of students in grades 7-9. A total of 329 students in grades 7-9 and 371 students in grades 10-12 had abnormal mental status. The detection rate of psychological abnormalities among students in grades 10-12 was higher than that of students in grades 10-12. Core self-evaluation had significantly negative correlation with various factors of mental health (P < 0.01). The worse the mental health, the higher the degree of mobile phone dependence, core self-evaluation played a mediating role between mental health and mobile phone dependence (8.03%). CONCLUSIONS: Core self-evaluation is an important factor affecting the mental health of high school students and mobile phone dependence. Educators should strengthen core self-evaluation of high school students to improve the mental health and reduce the mobile phone dependence.