When unexpected events occur,college students are more prone to some collective behavior which brings about serious effect by turning invisible public opinion into behaviorial opinion in nature.It is of great significance to master the characteristics of college students' behaviorial opinion,to implement timely intervention and guide it.The paper introduces college students' behaviorial opinion when unexpected events happen and analyzes the features of their behaviorial opinion.It then discusses universities' strategy of guiding opinion from four aspects: strengthening the political and ideological education,establishing information management system,paying attention to the performance of opinion leaders,using the role of positive public opinion.