Abstract: Along with the development in internet technology and popularization of the network applications, network provides a fair, open and just platform for the public to air opinions. Due to network characteristics, media properties and the particular social context reason, network colony accidents occur frequently. Based on the network group incidents reasons and by using Smelser's bonus plug theory model and agenda-setting mode formed in the process of solving domestic major events, this paper maps out the mechanism figure of the network colony accidents. The paper argues that there is deeper reason behind the network group incidents and that the transformation from general events to the colony accidents is a gradual process, and thereby puts forward the colony accidents guidance,prevention and control strategies based on the emergencies and Internet users.