Under the environment of great development about new media，network medias conduct a series of collaborative behaviors，such as forwarding public opinion information，under the effect of different interest mechanism due to the scarcity of information resources. And the wide range，fast forwarding behavior directly promote the development of the public opinion events. On the basis of the public opinion event of Fu xi meat in 2014，Social Network Analysis is employed to dissect the structure characteristics of collaboration network，to analyze the advantages and privileges of each media in the collaboration network，and to discuss the subgroups’ internal and external relations. The paper measures and analyses the network density，average shortest path，centricity，degree distribution and block models. The results indicate that，in the scale-free collaboration network of Internet medias，core medias promote the rapid dissemination of public opinion on a wide range of public opinion. Furthermore，in order to guide the benign development of the public opinion，the distributed nodes and subgroups should be the main object to be monitored according to the results of structural equivalence analysis.