Abstract: Finding the influential factors on the public perception and attitude towards the COVID-19 is conducive to improving the working mechanism for preventing and fighting the epidemic, reducing the interference of the epidemic on the production and life, and helping the government to introduce more targeted policies. Based on the survey results of the The Reaction of COVID-19 in Shanghai, this article took the public perception of the epidemic as the target variable, and used 12 variables such as occupation and education level as explanatory variables. Based on the CART and XGBoost model, we found out the important variables that cause the public to have different perceptions and attitudes, and re-evaluated whether the selected variables were reliable according to the model effect. With the help of association rules, the citizens affected by the COVID-19 were analyzed to identify the characteristics of this group. As the results showed, the expectation of income change as a result of the COVID-19, age and other variables were the main factors affecting perceived attitude. Therefore, judging the public’s psychological expectations, empathetic pain, and blind optimism or excessive pessimism are the key points that should be paid attention to at present. In addition, it is believed that people who think that the epidemic has an impact on life will generally spend a long time paying attention to the information of the epidemic, which will put too much pressure on themselves. They may have better education and be in good physical fitness, which means they may be more sensitive to the risk. Based on the findings above, this article comes up with some suggestions, such as strengthening employment guidance for the high-risk unemployed groups, making full use of new media publicity methods, and conducting appropriate psychological interventions on some specific groups.