<p id="p00005">Junior high school students are in a stage of rapid development in physiology and psychology, and they are prone to some mental health problems when facing stressful events in life. In addition, with the advent of the digital age, contemporary junior high school students have become digital natives, and their mental health is facing greater challenges. Therefore, the mental health care of junior high school students is a realistic problem that can not be ignored. The prevalence of mental health problems of junior high school students is an important topic in many fields, but the results of the research on this problem are not consistent, and the detection rate varies greatly across studies, which brings confusion to mental health workers. It is necessary to integrate the original research and draw more general and accurate conclusions from the macro perspective, so as to provide high-quality evidence support for precise intervention of mental health. Therefore, based on literature review, the present study focuses on the prevalence of internalizing problems including anxiety, depression, sleep problems, suicidal ideation, and suicide plans, as well as the prevalence of externalizing problems including self-harm and suicide attempt among junior high school students. <br/> By searching the Chinese National Knowledge Infrastructure database and Web of Science core collection database from 2010 to 2020, we obtained the final effective literatures including 50 articles about anxiety, 95 articles about depression, 21 articles about sleep problems, 26 articles about self-injury, and 30 articles about suicide. We used the software Comprehensive Meta-Analysis Version 3.3 and the random effect model for data analysis. The results showed that the prevalence of anxiety, depression, sleep problems, self-injury, and suicidal ideation were 26.9%, 23.9%, 16.7%, 22.4%, and 17.1%, respectively. The prevalence of suicide plans and suicide attempts were 6.6% and 3.9% separately. In addition, the moderating effect analysis found that in terms of anxiety, the moderating effects of publication year, measurement tools, detection time, grade, and economic region were significant, but the moderating effects of gender, only child or not and birthplace were not significant. In terms of depression, the moderating effects of measurement tools and detection time were significant, but the moderating effects of publication year, grade, gender, only child or not, birthplace, and economic region were not significant. In terms of sleep problems, the moderating effects of publication year, grade, gender and economic region were not significant. In terms of self-injury, the moderating effects of economic region were significant, but the moderating effects of publication year, measurement tools, grade, gender, only child or not, and birthplace were not significant. As to suicidal ideation, the moderating effects of measurement tools and gender were significant, but the moderating effects of publication year, grade and economic region were not significant. In terms of suicide plans, the moderating effect of grade was significant, but the moderating effects of grade, gender and economic region were not significant. Finally, in terms of suicide attempts, the moderating effect of publication year is significant, but the moderating effects of grade, gender and economic region were not significant. <br/>In conclusion, junior high school students faced different levels of mental health problems, among which the prevalence of anxiety, depression, and self-injury rank in the top three. The prevalence of mental health problems of junior high school students showed a deteriorating trend with the development of the years, especially anxiety and suicide attempt. The prevalence of mental health problems of junior high school students is affected by the inconsistency of measurement tools, detection standards and detection time. In addition, the prevalence of mental health problems increased with grade, especially that of anxiety; The prevalence of mental health problems in girls is higher than that in boys, especially that of suicide. Students in the central and western regions in China are more likely to have mental health problems, especially anxiety and self-injury. In the future, we should develop scientific measurement tools and screening standards based on Chinese culture, and establish a dynamic monitoring system of mental health and a school mental health service system.