Information broadcasting of micro-blog network can help users to acknowledge its broadcasting characteristics and rules, to provide theoretical basis and practical instruction for scientific monitoring and dissemination of public opinions. This paper adopts micro-blogs of SINA website as the research object to analyze the topology feature and information broadcasting rules of user. It makes a statistics on network topology of confusion network composed by social users, and verifies the influence on information broadcasting caused by network structure. Then it further studies the transmission characteristics and comment characteristics micro-blog messages, providing the influencing factors of broadcasting network with given cases. During the experimental process we analyze the broadcasting effects under different conditions, showing the characteristic of our model is in accordance with real situation.