Abstract: Construction of major project attracts wide attention from the public as it bears heavily on national economy and people's livelihood. Public opinion will have a negative impact on government credibility and project reputation. It will also weaken the social benefits of major projects and affect social stability and regional economic development. Based on the different interest concerns of network groups, a dissemination model of public opinion is established. Firstly, the interaction between public risk perception and the choice of government public opinion disposal behavior is analyzed. Secondly, the government decision-making behavior and the government critical value management model under the consideration of public trust value are studies, and a calculation model of optimal time node for the government to choose the positive disposal measures under different directions of public opinion dissemination is established. Finally, the validity of the model is proved through case study and this study provides decision support for decision-making management departments to effectively deal with public opinion information and resolve public opinion crisis.

Key words: major project, network public opinion propagation, risk perception, behavior choice