Abstract: Traditional Chinese medicine (TCM) has rich experience in the diagnosis and treatment of epidemics, but the basic concepts and diagnosis and treatment strategies of TCM for epidemics have not yet formed a common understanding. This paper preliminarily constructs a diagnosis and treatment system of TCM epidemics from the perspective of "type differentiation-stage differentiation-syndrome differentiation"by combing the basic concepts of the etiology, pathogenesis, and identification of epidemics, taking state-target differentiation and treatment as the general principle. First, the epidemics are divided into five types: cold epidemics, warm epidemics, cold-damp epidemics, damp epidemics, and miscellaneous epidemics; then, according to the overall course of the epidemics, they are divided into four stages: "initial stage-peak stage-extreme stage-relapse stage", the initial stage is the stage of exterior syndromes, the peak stage is the stage of heat peak, the extreme stage is the stage of internal closure and external loss, and the relapse stage is the stage of recovery of the healthy qi and retreat of the evil qi; finally, on the basis of staging, combined with the syndrome characteristics of various epidemics (five types of background diseases) at different stages, the syndromes are divided demonstratively. Through the construction of a modern diagnosis and treatment system of TCM epidemics, the basic theoretical concepts and basic diagnosis and treatment strategies of epidemics can be clarified, various new and emerging infectious diseases can be actively responded to, and a diagnosis and treatment plan for a new and emerging infectious disease can be quickly constructed.