With the popularization of Internet, the number of netizens in China has been on the rise, and both public opinion and content have been rising. As the emergency has its specific life cycle, network emergencies also have their time points. According to the changes in public opinion, the network of public opinion on the dissemination of emergency control should be paid attention to, to avoid group polarization and public opinion of the multi-level derivative. This paper analyzes the construction of network public opinion evaluation index system, build network public opinion forecast model and unexpected events network public opinion early warning measures; researches on the emergency network public opinion dissemination and early warning mode.