Experimental: experimental group of ordinary COVID‐19:
Xiyanping injection, 10–20 ml daily, Qd, the maximum daily does not exceed 500 mg (20 ml) + lopinavir tablet or ritonavir tablet + alpha‐interferon nebulization, for 7–14 days,
Active comparator: control group of ordinary COVID‐19:
Lopinavir/ritonavir tablets, two times a day, two tablets at a time; alpha‐interferon nebulization
Experimental: experimental group of severe COVID‐19:
Xiyanping injection, 10–20 ml daily, Qd, the maximum daily does not exceed 500 mg (20 ml) + lopinavir tablet or ritonavir tablet + alpha‐interferon nebulization, for 7–14 days