At present, the research on the pathology of malignant infectious diseases has become one of the hot spots in the field of medical care. Faced with the risk of sporadic outbreaks of infectious diseases, regional infectious disease risk assessment and analysis has important theoretical and practical significance. Especially in the early stages of infectious disease outbreaks, the assessment results play an important role in helping to develop reasonable prevention and control strategies and suppressing further losses caused by infectious diseases. This study proposes a regional infectious disease risk assessment method based on D-S (Dempster Shafer) evidence theory. Firstly, based on existing research results, construct an infectious disease risk model. Then, map the regional risks and the actual situation of infectious diseases into the risk model to obtain the necessary data for risk assessment. Next, the fusion assessment results of regional infectious disease risk are calculated using the D-S theory. The assessment results can demonstrate the level of infectious disease risk in the region and the weaknesses when the region faces different types of infectious diseases. Finally, the study verifies the effectiveness, rationality, and feasibility of the proposed method through case design and analysis.