This paper uses the method of qualitative discourse analysis and quantitative analysis of social network，treating Sina-Weibo as the only platform for social network analysis on the Shanghai Stampede Incident.According to the Degree Centrality and the Freeman Betweenness Centrality，we found that four kinds of roles have their effects on agenda setting，rumor clarification，bridge construction and supporting including the official media，the government，the celebrity and the public individually.In this situation，a game between the four，they jointly promoted the development of Weibo's consensus.