Misinformation has become prevalent since the beginning of the COVID-19 pandemic. To understand why people believe and share misinformation, we conducted a nationwide survey during the COVID-19 outbreak in China. We found the indirect effects of COVID-19 risk on people's information accuracy judgment and associated information sharing intention through people's emotional states. People faced with a higher level of COVID-19 risk (measured by a 7-day moving average of daily new deaths or new cases) experienced weaker positive and stronger negative emotions, and heightened emotionality (both the positive and negative emotions) was associated with increased belief in and greater likelihood to share the COVID-19 information regardless of veracity. We also found that only the negative emotion mediated the relation between the COVID-19 risk and the truth discernment regarding accuracy judgment. However, the mediating effect of negative emotion disappeared among people with high analytic thinking ability. These findings suggest that the analytic thinking ability could moderate the destructive relationship between negative emotion and accuracy discernment. Based on a large sample, our findings provide actionable insights for the policymakers to respond to the spread of misinformation appropriately and promptly during the pandemic.