Abstract: The network has become the daily essential channel to publish and access information for people, more and more consumers rely on network access to emergency events, so the network public opinion is becoming more and more important in the development process to promote the event. This article is based epidemic model theory to build an imitation and contagion model in the evolution of network public opinion on food safety incident, which aims to study the infection mechanism and behavior of the Internet users in the process of public opinion spread of food safety incidents. The study takes the "ShuanghuiClenbuterol" events for an example, simulates and verifies the correctness of the model. It is expected to provide a reference to the stakeholders of food safety incidents who will correctly respond to imitation and contagion behavior of Internet users in the process of the network public opinion evolution.

Key words: emergency events, network public opinion, food security incidents, imitation and contagion