Efficacy and Safety of Jaktinib in Participants With Severe Novel Coronavirus Pneumonia(COVID-19)

Inclusion Criteria: * 18 years of age, male or female; * The Participants was diagnosed with novel coronavirus pneumonia; * It meets the heavy-duty standards of the new coronavirus pneumonia diagnosis and treatment protocol (version 9). * Participants who voluntarily sign informed consent. * The National Institute of Allergy and Infectious Diseases Sequential Scale (NIAID-0S) score is 5 or 6; Exclusion Criteria: * Participants who cannot take orally, or are suspected to be allergic to Jaktinib, similar drugs or their excipients, or have severe gastrointestinal dysfunction that affects drug absorption; * Participants who have received the following treatments within the specified time window before randomization: 1. Participants have received Janus kinase (JAK) inhibitor, interleukin 6 (IL-6) inhibitor, IL-1 inhibitor, tumor necrosis factor (TNF) inhibitor, T cell or B cell depletion agent, interferon and other immunosuppressive drugs within the first two weeks of randomization, except glucocorticoid; 2. Systematically used CYP 3A4 potent inhibitor or potent inducer in the first five drug half lives at random; * Immune deficiency;