New media has continuously developed and penetrated into all aspects of social life, which leads to online public opinion emerging in endlessly. Many researches tend to discuss the guiding-measures, but ignore the theoretical summary of the influencing factors for the generation and development of online public opinion. In this article, we would adopt case analysis from big data, which in the foundation of those typical public opinion cases from January 2018 to March 2019. And we fnd that the importance, ambiguity, accessibility and sensitivity of information are directly related to whether it can develop into a storm of online public opinion storm, and these factors are positively correlated with the formation of the network media storm. We can come to the conclusion that the new media storm formula: Storm of online public opinion=Importance×Ambiguity×Sensibility×Reachability.