Objective To investigate mental status of front-line nurses in Zhengzhou city during dual disasters of flooding and COVID-19 and to provide reference for targeted intervention. Methods A total of 206 nurses who participated in flood disaster and COVID-19 rescue and prevention were surveyed by utilizing a general information questionnaire, the Generalized Anxiety Disorder 7-item, the Kessler Psychological Distress Scale and the Psychological Capital Questionnaire.And 10 of them received one-on-one in-depth interview to express their feelings. Results The median score of generalized anxiety disorder was 5（4,7）.The total score of psychological distress and psychological capital was （24.27±6.58） and （79.84±13.62） respectively. Psychological capital was negatively correlated with psychological distress （r= -0.678,P＜0.01）, whereas anxiety was positively correlated with psychological distress （r= 0.602,P＜0.01）.The age of the youngest child, work length, anti-disaster and anti-epidemic experience, psycholo-gical capital and anxiety were the influencing factors of psychological distress （adjusted R2=0.618,P＜0.05,P＜0.01）.Five themes were identified in the qualitative research: lack of experience and insufficient knowledge, heavy workload, concerns about relatives, lack of psychological counseling and social support. Conclusion The front-line anti-disaster and anti-epidemic nurses have different degrees of psychological distress during dual disasters of flooding and COVID-19, which is affected by many factors. Hospital managers should pay attention to the issue, strengthen disaster preparedness training and improve psychological counseling programs, so as to improve nurses′ disaster response ability and mental health.