In the face of a pandemic, social media have found to be vital information channels that might exert a positive influence on people's preventive behaviors. However, little is known about the underlying processes that may mediate or moderate the relationship. The present study examined the relation between novel coronavirus disease (COVID-19) information consumption on social media and preventive behaviors, as well as the mediation role of personal responsibility and moderation role of health orientation. A sample of 511 online participants (mean age = 32.47 years) responded to anonymous questionnaires regarding COVID-19 information consumption on social media, health orientation, personal responsibility, and preventive behaviors. Bias-corrected bootstrap method was used to test the moderated mediation model. Results indicated that after controlling for participants' age, gender, education, income, and insurance, personal responsibility mediated the relationship between COVID-19 information consumption on social media and preventive behaviors. Meanwhile, the direct relation between COVID-19 information consumption on social media and preventive behaviors, and the mediation effect of personal responsibility were moderated by health orientation. The present study can extend our knowledge about how risk information consumption on social media is related to one's behavioral outcomes. Implications and limitations about the present study are also discussed.