In order to improve climate resilience, the world is working to explore effective ways to mitigate water risks. The flood control problem has the dual attributes of nature and society. It is necessary to combine nature-based solutions with social institutional means, and adopt a more systematic strategy to realize the dual management of natural ecology and social production. Using the participatory system dynamics model and scenario analysis method, this paper selects Poyang Lake as a case to comprehensively examine the potential of nature-based solutions and social institutional means in reducing flood risk, as well as the derived social, economic and ecological benefits. The results show that : (1) Nature-based solutions and social systems gradually adjust the key factors affecting the scale of floods through the mechanism of continuous feedback and circulation to achieve the purpose of flood control and flood mitigation.(2) On the basis of flood control benefits, nature-based solutions and social institutional means also derive ecological, economic and social benefits, but the effectiveness of nature-based solutions presents a more obvious time lag.(3) The two strategies of nature-based solutions and social institutional means complement each other. In order to give full play to the long-term effectiveness of nature-based solutions, it is necessary to enhance the safety awareness, financial support, institutional cooperation and capacity building of flood control at the social level in terms of social institutional means. To maintain the long-term effectiveness of social institutional means, there must also be a natural-based solution as a basis. The optimal combination of the corresponding measures of the two types of management methods is more conducive to the management of flood risk and the generation of multiple common benefits.