The work studies how to analyze and visualize massive emergency data on the topic of epidemic data visualization. Under the background of massive data and complex sources, the advantages of data visualization in data reporting of public health emergencies are explored based on the methodology of visualization design. With the design of Data Visualization Analysis of COVID-19 Epidemic in Chongqing as an example, the data visualization process from design methods to conclusion is concretely analyzed.Moreover, the data analysis and expression methods for the epidemic visualization design applied to public health emergencies are analyzed and sorted out, which provides certain supplements for the design intervention and design methods of data visualization of public health emergencies.