Objective  To explore the clincial characteristics and therapy of hydrochloric acid gas inhalation-induced acute respiratory distress syndrome (ARDS). Methods  Clinical date of an ARDS following inhalation of hydrochloric acid gas treated by bilevel positive airway pressure (BIPAP) vetilation with pirfenidone (PFD) was reported. Literature was reviewed to investigate the treatment characteristics. Results  A 33-year-old male patient was admitted to our department due to cough, expectoration, chest distress and shortness of breath after hydrochloric acid gas inhalation. Lung CT showed diffuse interstitial pulmonary damage. Oxygen saturation decreased to 75%. The patient was diagnosed as “aspiration pneumonia and ARDS”. The oxygenation and clinical symptoms were improved via BIPAP ventilation combined with PFD. The fibrous foci of two lungs reduced. Conclusion  Early application of BIPAP can significantly reduce the intubation rate and mortality of ARDS.  PFD can delay the process of pulmonary fibrosis, and even reversed.