Harmonious social public opinions are indispensable to a harmonious society. Also, social public opinions as part of social management are very important. In the existing research field of the models of opinion dynamics, natural science focuses more on the mathematics or physics mechanism of opinion with quantitative methods, which produces more abstract results and may detach research from the actual media events. Therefore, this paper proposes the methodology-method-technology-evidence mode for modeling and simulation of social public opinion during unconventional emergencies with interdisciplinary perspectives from management, systems and psychology based on system methodology and visual simulation platform, which aims to grasp the mechanism of social public opinion formation and evolution for achieving the functions of early warning and forecasting.