Abstract: In the new media era, the dissemination of microblog public opinion derived topics is becoming more and more popular, and the research on the dissemination law of this kind of public opinion has become the focus of scholars. Based on the improved SEIR public opinion communication model, considering the transformation of immune people into new topic communicators under the attraction of new topics and the competition in the communication of different topics, this paper constructs a microblog public opinion derived topic communication model, calculates the communication threshold through differential equation for analysis, and uses Lotka-Volterra competition model to analyze the competitive evolution of different topics. Based on the real case, the model is simulated by using NetLogo and MATLAB software. The feasibility and effectiveness of microblog public opinion derived topic communication model are verified through specific cases. The results show that the situation that immunized people start to spread new topics again expands the scale and influence of public opinion, and there is competition between different topics of the same public opinion, and its competition increases the impact of public opinion communication. Finally, it provides some specific strategies and suggestions for the government to effectively deal with the communication of microblog public opinion derived topics.

Key words: Microblog public opinion, Public opinion dissemination, Derivative topic, Public opinion analysis, NetLogo simulation, Lotka-Volterra competition model