It's of great significance of understanding and controlling the micro-blog world of college students in the dissemination of false information, sensitive information, as well as timely and reasonable guidance, the implementation of the coordination of the governance of micro-blog rumors. After analyzing the text syntactical structure features of online rumors, it presents a simple way of rumor detection based on LanguageTool. The experiment on Sina Weibo shows that more than half of the rumors can be detected with only 5 main types of rumor rules.