This study aimed to explore the impact that coping styles and social support have on the mental health of medical students by constructing a corresponding structural situation model that reveals the complex relationship between these three factors. In doing so, it seeks to help medication students better manage mental health problems. The online study was conducted between March 6, 2021 and May 6, 2021. A total of 318 participants from multiple medical schools were involved. The general information questionnaire, simple coping style questionnaire (SCSQ), perceived social support scale (PSSS) and symptom checklist 90 (SCL-90) were used to collect relevant information from the subjects by snowball sampling. An independent t-test, ANOVA, Pearson correlation coefficient analysis, and intermediary effect analysis were all used to analyze the relevant data and construct the structural equation model. There was a significant difference in SCL-90 between medical students and national college students (1.78±0.70, P < 0.001), and the positive rate of mental health status was as high as 40.3%. Sleep quality, regular diet, and positive coping style were positively correlated with mental health (P < 0.01), while negative coping styles and total scores of coping style as well as family, friends, and other sources of social support and total scores of social support were negatively correlated with mental health problems (P < 0.01). Positive and negative coping styles have an impact on mental health through the mediating effect of between social support and coping styles, as well as in the direct pathway. The mental health status of medical students was significantly poor. Medical schools should thus pay close attention to the mental health status of students and encourage them to develop healthy living habits, optimize coping styles, and establish stable sources of social support to improve their psychological wellbeing.