Rapid and precise epidemiological investigation is one of the most important control measures for implementing "scientific and precise, dynamic zero-COVID -19" policy in China. Compared with ordinary locations, medical institutions have a large flow of people and a complex layout, making it difficult to investigate. Moreover, most people involved in the epidemic are patients and health care workers, which puts higher demands on the precision of epidemiological investigation. When local epidemics occur, the resources for epidemiological investigation at disease prevention and control are extremely scarce. How to simultaneously utilize medical institution resources to achieve large-scale and multi-location precise epidemiological investigation is an important issue in epidemic prevention and control. Since the outbreak of COVID -19, the infection control team of West China Hospital has carried out active and in-depth exploration for the epidemiological investigation in medical institutions, and gradually formed a precise epidemiological investigation management mode with distinctive features of West China Hospital. This article combines the experience of infection control team at West China Hospital to elaborate the construction mechanism, ta-lent selection, training system, and assignment of responsibility in medical institution epidemiological investigation team. Meanwhile, it proposes the challenges faced by medical institutions in the construction of professional epidemiological investigation talent team under the current situation, as well as the development direction for the professionalization of infection control talents in the future.