Objectives: In order to explore the role of psychological capital between psychological stressresponse of COVID-19 and coping styles. Methods: 548 postgraduates in a condition of the epidemicprevention and control normality were attempted the online test including the psychological capital scale,the psychological stress response scale and the coping style scale. Results: Psychological stress responsewas negatively correlated with positive coping style (r=-0.43, p<0.01), while positively correlated withnegative coping style (r=0.10, p<0.01). The psychological capital plays a mediating role in the relationshipbetween psychological stress response and positive coping style, with effect value of 60.76%. Conclusions:Improving the psychological capital is conducive to positive coping style when the individual is under thestress of COVID-19.