Background: The coronavirus disease 2019 (COVID-19) has spread to 215 countries around the world. In the studies of responding to public health emergencies, most of them are focused on health systems, local governments or medical organizations, but less on individuals. Medical staff, however, are the core strength for responding to public health emergencies. The aims of this study are to investigate the status of medical staff’s emergency capacity during the Pandemic and to provide intellectual support for further enhancing the medical staff's ability to ensure the smooth operation of medical rescue. Methods: This study conducted a cross-sectional survey of four hospitals, which were designated to treat patients with COVID-19 in China. Based on the emergency capacity system for infectious diseases of medical staff, an improved Emergency Preparedness Information Questionnaire was used to evaluate the emergency capacity of medical staff. Linear regression and one-way analysis of variance were used to test the difference in the emergency capacity of medical staff; Spearman correlation analysis was used to study the correlation between self-efficacy and emergency capacity of medical staff. Results: The overall emergency capacity of the surveyed medical staff was at a medium level. There was a correlation between emergency capacity and age, working years, position, educational background and area where medical staff work. Emergency capacity was not related to the hospital grades. Emergency capacity was significantly related to whether medical staff had participated in frontline Pandemic prevention work. There was also a positive correlation between emergency capacity and self-efficacy of medical staff. Conclusions: The results highlighted the importance of the training mechanism for emergency personnel. The emergency input for public health emergencies should be increased to improve the emergency capacity of medical staff. In addition, it is necessary to pay attention to the mental health of medical staff.