Inclusion Criteria:
1. Patients who sign the informed consent form.
2. Age 30\~80 years old, gender is not limited.
3. Patients with pulmonary fibrosis who have obvious pulmonary fibrosis symptoms, signs, and HRCT abnormalities, and are diagnosed as pulmonary fibrosis patients specified in this protocol, and have poor effect of existing treatment regimens or do not accept existing treatment regimens
Clinical basis for diagnosis of pulmonary fibrosis:
1. Abnormal pulmonary function, including restrictive ventilatory dysfunction and gas exchange disorder;
2. Typical fibrotic manifestations were found on HRCT, such as interstitial changes, grid-like changes or honeycomb lungs
Exclusion Criteria:
1. Patients suffering from any of the following diseases: active tuberculosis, lung abscess, aspiration pneumonia, lung tumor, pulmonary edema, atelectasis, pneumothorax, pleural effusion, pulmonary embolism, pulmonary eosinophilic infiltration, pulmonary vasculitis and immunosuppression or immunodeficiency (including: hepatitis B surface antigen, hepatitis C antibody, AIDS antibody, syphilis antibody test positive);
2. Patients with active infection within 4 weeks;
3. Patients with acute exacerbation of pulmonary fibrosis within 4 weeks or/and those who require high-flow oxygen (oxygen concentration greater than or equal to 40% or oxygen flow greater than or equal to 5L/min), non-invasive or invasive ventilator-assisted ventilation
4. Patients with a history of tumor or current tumors;
5. The patient has a severe life-threatening disease and is expected to survive less than 12 months;
6. The patient has leukopenia (neutrophil count\< 1000/mm3);
7. Patients with severe renal impairment: creatinine clearance \< 30ml/min/1.73m2 or serum creatinine \>265μmol/L (\>3mg/dL);
8. Patients with liver disease or severe liver function impairment: ALT, AST \> 2 times the upper limit of normal value;
9. Those with central nervous system dysfunction, such as convulsions, impaired consciousness, history of epilepsy or seizures; Have a clear history of mental disorders, or a history of psychotropic substance abuse or drug abuse
10. Long-term use of glucocorticoids for treatment of more than 10 mg of prednisone or equivalent, immunosuppressants or antifibrotic drugs, such as penicillamine, colchicine, cyclosporine A, TNFα antagonists, imatinib, IFN-γ, azathioprine, cyclophosphamide;
11. Women who are pregnant, breastfeeding or do not use proper contraception;
12. Those who are allergic to known ingredients of drugs and who are known or suspected of being allergic to the active or inactive ingredients of the study drug;
13. Allergy to acetaminophen or history of hypersensitivity reactions;
14. Alcohol abuse (defined as drinking \>2 units per day/1\>4 units per week, drinking 1 unit equivalent to 360ml of beer or 45ml of spirits with 40% alcohol content or 150ml of wine) or drug abusers;
15. Any situation that the investigator believes may increase the risk of the patient or interfere with the clinical trial, and the patient is not suitable for entering the investigator.
