Objective To explore the relationship between family environment， coping style and anxiety and depression， and the mediating mechanism of coping style in the process of family environment affecting anxiety and depression. Methods A total of 1 950 freshmen from a university in Daqing were investigated with Family Environment Scale and Simple Coping Style Questionnaire， Self-rating Anxiety Scale and Self-rating Depression Scale. Results Among 1 902 recycled questionnaires， there were 1 846 valid questionnaires， with an effective rate of 94.67%. In all the students， there were 471 male（ 24.15%） and 1 432 female（ 73.44%）. Compared with male， female freshmen scored higher in emotional expression， conflict， success， organization， control dimension and positive coping（ P＜0.05）. All dimensions of family environment were significantly correlated with coping styles， anxiety and depression scores（ P ＜ 0.01）. The influence of family environment on freshmen's anxiety and depression was partially mediated. Chi square freedom ratio （χ2/df） was 23.158 and 16.252； Goodness of fit index（ GFI） was 0.947 and 0.960； Adjusted goodness of fit index（ AGFI） was 0.893 and 0.921； Root mean square error approximation（ RMSEA） was 0.108 and 0.090. It is suggested that the fitting degree of the two models was ideal. Conclusions Family environment and coping style are significantly related to anxiety and depression. Family function can directly affect freshmen's anxiety and depression， and can also indirectly affect anxiety and depression through coping style. It is suggested that attention should be paid to the guidance and correction of college students' coping styles， which is of great significance to the psychological health of college students.