By analyzing and excavating data from the health hotline 12320 in Guangzhou, in combination with the original monitoring system of infectious diseases, the paper constructs a monitoring and early warning system of emergent public health affairs based on data from the hotline and introduces the method and process of early warning. This system can utilize consulting information from 12320 to analyze and process data. Also, it can be used as the tool for aggregating public health information and monitoring public opinions.