According to the short life cycle of food safety of public opinion and the disciplinary development curve, it is feasible for prediction of public opinion hot-degree to use improved entropy and Markov model. The paper selects “dirty porterhouse of one well-known catering enterprise” food safety public event in 2016, setting up comprehensive evaluation index system by AHP: the media, net citizen and government as the criterion level. Index weight can be calculated with improved entropy method. The state transition matrix will be constructed and food safety of public opinion's change interval will also be predicted by Markov. The results show that the comprehensive construction of the index system and the improved entropy weight method indeed improve the accuracy of the Markov model, and effectively realize the prediction of food safety public opinion finally.