This paper studied the public opinion dissemination mechanism of public health events such as avian influenza on WeChat. We collected 25,572 posts related to “avian influenza” and “H7N9” from WeChat accounts and proposed the NRT model to simulate the spread of avian influenza public opinion in WeChat. Fitting results show that it can well explain the information dissemination process and mechanism within the WeChat public account. Then the influence of model parameters on the propagation of network public opinion is further studied. Our research can provide a theoretical basis for network public opinion prediction and prevention, and has great significance for the stability of the network environment.