Abstract: As a form of social public opinion, network public opinion has the characteristics of high degree of social concern, fast transmission speed and wide range of influence, which often breaks out suddenly and makes people unprepared. Because the earthquake disasters are directly related to people’s life and property, the earthquake emergency is very easy to cause network public opinion, in which there are many kinds of rumors. If not handled in time or improperly, it will bring more serious social impact. Taking“Sanya earthquake”topic as an example, we will analyze the main types of construction subject of“Sanya earthquake”topic, and the main content, public emotion and communication area of its public opinion. Opinion and suggestions on emergency management of public opinion in earthquake emergencies and the guidance of public opinion will be discussed.