The efficacy of pirfenidone capsules is to reduce the accumulation of inflammatory cells, attenuate the proliferation of fibroblasts and the synthesis of related products, and act as antifibrotic and anti-inflammatory. Pirfenidone capsule is a kind of immunosuppressant, clinically used in the treatment of mild and moderate idiopathic interstitial pulmonary fibrosis. Its mechanism of action is still unclear, may be to reduce the accumulation of inflammatory cells triggered by a variety of stimuli, as well as attenuate the fibroblasts by cell growth factor stimulation triggered by cell proliferation and the production of related products. It should be noted that the use of pirfenidone capsules is prohibited for those who are allergic to any component of the drug, pregnant women, lactating women, people with severe liver disease, severe kidney disease, people who need dialysis treatment, and avoid the concomitant use of fluvoxamine during the administration of the drug. Some patients may experience adverse reactions such as dyspepsia, vomiting, nausea, anorexia, skin rash, hepatic impairment, drowsiness, dizziness, unsteady walking, etc. If the discomfort is more serious, patients should consult a doctor in time. Patients should follow the doctor’s instructions to use pirfenidone capsules, avoid self-medication, so as not to induce side effects, or affect the condition.