Abstract: The COVID-19 epidemic has had a certain impact on China’s economic development, and changes in public psychology are one of the major factors that determine the breadth and depth of its impact. Through establishing an expectation model, the study finds that public psychological expectations are crucial to economic operations, and their changes will greatly affect policy choices. As the psychological activities of human beings, psychological expectations have an “contagion” mechanism. The paper adopts persuasive immune model to simulate the “contagion” mechanism of psychological expectations. The results show that public psychological expectations can be reasonably guided by investigating social expectations accurately, decreasing their rate of “contagion” , increasing their rate of “immunization” and reducing the number of initial vulnerable people.