To evaluate the efficacy and safety of Anluohuaxian in blocking the progression of pulmonary fibrosis and improving lung function in patients with COVID-19.

In clinical institutions that enroll patients with corona virus disease 2019, two arms, multi-center, randomized and controlled methods are adopted. Patients are divided into two groups, Anluohuaxian combined with regular treatment group and regular treatment group. 750 patients are expected to be enrolled and the cases are allocated according to the ratio of 2( Anluohuaxian combined with regular treatment group): 1(regular treatment group).

Inclusion Criteria:

1. Confirmed COVID-19, and the nucleic acid test of respiratory specimens such as sputum or nasopharyngeal swabs is negative twice after the treatment (sampling interval is at least 24 hours);
2. Negative nucleic acid test of respiratory specimens such as sputum or nasopharyngeal swabs during screening visits;
3. High-resolution CT of the lung (HRCT) indicates pulmonary fibrosis (thickness of lobular septum, honeycomb-like changes, with or without bronchial / pleural distraction);
4. Voluntarily participate in research and sign informed consent.

Exclusion Criteria:

1. Combined with severe heart, lung (diagnosed with interstitial lung disease, bronchial asthma, chronic obstructive pulmonary disease, etc.), liver and kidney disease or with endocrine, rheumatic, neurologic, malignant and other systemic diseases;
2. Have been diagnosed with connective tissue disease;
3. Pregnant or lactating women;
4. History of mental disorders, substance abuse or dependence;
5. Have used other anti-pulmonary fibrosis drugs in the past 14 days, such as nidanib, pirfenidone, penicillamine, colchicine, tumor necrosis factor alpha blocker, imatinib, glucocorticoid hormones, morphomycodyl esters, azathioprine, cyclophosphamide, interferon-γ, and traditional Chinese medicine;
6. Researchers consider it inappropriate to participate in research;
7. Participating in other clinical research.