Vulnerability is a vital component of risk and the principal element of disaster impacts. Increased attention has lately been given to the people’s vulnerability to natural hazards and disasters. However, strikingly little attention has been paid to the driving factors affecting the social media users’ vulnerability to online public opinion of emergency in the context of online environment. In this paper, a data-driven approach is proposed to investigate what and how driving factors associated with users’ vulnerability to online public opinion of emergency in social media. A total of 65,635 Sina Weibo - China’s microblogging website posts about Jiuzhaigou earthquake are used in this study. Principal component analysis is employed to extract the four factors from 13 variables and the ordered logistic regression results demonstrates that “the exposure of online public opinion” and “the negative reaction of users” have positive impact on the vulnerability of social media users, while “the resistance of users” and “the positive reaction of users” is significantly and negatively correlated with the vulnerability of social media users. As a theoretical implication, this research promotes the application of disaster research as well as provides a new perspective for risk analysis of online public opinion, and as a practical implication, emergency agencies can mitigate the risk of public opinion in emergency by reducing the vulnerability of social media users.