To present information on infectious diseases caused by viruses clearly and track the changes of data in real-time, data visualization can be used preferentially considering that it can identify problems behind data accurately. In this paper, based on the SuperMap Online platform and Tianditu, a national platform for common geospatial information services, a risk level map of infectious diseases distribution area is made by Web GIS and cartography. Meanwhile, the platform plays an important role in information collection, management, analysis, prevention and control, and release of measures when a major health event spreads. The method shows many advantages, such as various visualization means, ease to be published and shared, simple operation, and programming realization, which may be taken as technical references for solving the same type of visualization application problems. The research also facilitates the data visualization and monitoring of the spread of infectious diseases in major health events, and can effectively provide services for monitoring, decision-making, dispatching, and handling the spread of infectious diseases.