This center intends to conduct a single-center, randomized, placebo-controlled study to evaluate the effectiveness and safety of Nintedanib ethanesulfonate soft capsule in the treatment of pulmonary fibrosis in patients with moderate to severe COVID-19.

This center intends to conduct a single-center, randomized, placebo-controlled study to evaluate the effectiveness and safety of Nintedanib ethanesulfonate soft capsule in the treatment of pulmonary fibrosis in patients with moderate to severe COVID-19. The number of cases is estimated based on the following:

This exploratory trial is expected to complete 80 case studies (randomly divided into control group and test group each with 40 cases), and the expected drop-out rate is not more than 20%, so the total number of cases is 96. Placebo control group:

Empty capsules with the same appearance and ingredients as Nintedanib soft capsules: one capsule at a time, twice a day, with an interval of about 12 hours each time. Continuous medication for 8 weeks.

Nintedanib Nintedanib cloth sulfonate soft capsule treatment: According to the drug manual recommendation, give Nintedanib cloth sulfonate soft capsule 150mg twice daily with an interval of about 12 hours each time, with food. Continuous medication for 8 weeks.

Inclusion Criteria:

1. 18-70 years old (including 18 and 70 years old), regardless of gender;
2. Infection with new coronavirus pneumonia was confirmed by throat swab nucleic acid test. Patients with severe and critical illness were clinically judged. The symptoms of acute infection have been alleviated after treatment (at least 14 days after onset, no fever for more than 3 days), and the disease is recovering Within three months;
3. CT examination of patients with multiple fibrotic shadows in both lungs;
4. Blood routine, liver, and kidney functions are within the controllable range: such as the normal upper limit of plasma total bilirubin and creatinine ≤ 1.5 times; AST, ALT, LDH ≤ 2 times the normal upper limit; sufficient hematopoietic function: such as white blood cells ≥4.0 × 109 / L, platelets ≥100 × 109 / L;
5. Signed informed consent.

Exclusion Criteria:

1. Previous history of chronic bronchitis, emphysema, interstitial lung disease or pulmonary heart disease;
2. Combining with other serious diseases: such as those who have suffered myocardial infarction and uncontrollable diabetes within 6 months, and are considered unsuitable to participate in the trial;
3. People with active peptic ulcer;
4. Patients during pregnancy and lactation
5. Patients with mental illness or others who cannot cooperate effectively;
6. Researcher judges uncomfortable to participate in trial