Abstract: With the adjustment of China's COVID-19 policies and measures, the treatment of infected patients, especially the severe and critically ill patients, has become the focus of all medical staff at this stage. Since the outbreak of the pandemic, Peking Union Medical College Hospital has accumulated rich experience in this field. Based on the updated international evidence-based knowledge, the multidisciplinary expert group of COVID-19 at Peking Union Medical College Hospital has compiled a set of operational recommendations. Adhering to the evidence-based, concise, and clinically operable principles, these recommendations for diagnosis and treatment integrate the latest research evidence. For clinical issues that lack evidence, certain recommendations are given based on the frontline clinical working experience and expert opinions. The purpose is to enhance medical staff's understanding of COVID-19 infection and its critical illness and improve patient care.