As a new media form in information era, micro-blog has become the main communication channel. On one hand, it delegates the right of communication .On the other hand, more opinion leaders assemble this platform and expand the centralization effect. Especially in the public event propagation, micro-blog opinion leaders are becoming the public opinion formation and development the important force. This article begins with the characteristics of micro-blog opinion leaders, discuss the guiding role of opinion leaders in public events and suggest how to make full use of micro-blog opinion leaders to guide the public opinion.