“China, Japan and South Korea + Infectious Disease Prevention and Control” is an important project under the “Trilateral+X” cooperation framework. The outbreak of the COVID-19 has made the further advancement of this project urgent and focused. While demonstrating the practical feasibility of the “China, Japan and South Korea + Infectious disease prevention and Control” project, this paper summarizes the consensus, intention and measures reached by the three countries in the prevention and control of infectious diseases, and divides them into three categories: trade cooperation, production cooperation and prevention and control cooperation. Then, the GTAP model is used to simulate the potential value of different cooperation programs and specific measures in influencing the changes of GDP, social welfare and industrial output of China, Japan and South Korea as well as other countries or regions in the world. Finally, the paper gives some policy implications based on the empirical results.