This study investigated the mental health status of medical students in China, and analyzed the influencing factors in order to provide evidence for mental health education for medical students. A stratified cluster sampling method was used to recruit medical students from Huazhong University of Science and Technology, China. The questionnaire survey on general information and Symptom Checklist 90 (SCL-90) were used for investigation and analysis. The results showed among the 1137 valid questionnaires, 278 (24.45%) participants had SCL-90 score ≥ 160. The top three mental problems of medical students were obsessive-compulsive disorder, interpersonal sensitivity and depression in terms of the factor score ≥ 2.5 and the number of participants who reflected on the diseases. The third-year medical students had the worst mental health status, and fifth-year medical students had the best mental health status. Students from rural area had more psychological problems than those from urban area; furthermore, students with high professional satisfaction, those who were the single child of the family, non-poor students, and those whose parents had high education level had better mental health status. It was concluded that the mental health of medical students is not optimistic in China. Medical students have some mental health problems of different degrees. Factors that influence the mental health of medical students include academic pressure, professional satisfaction level and family environment.