Abstract: Acute lung injury (ALI) is a common critical disease in ICU. It is usually caused by a variety of direct or indirect injury factors, and has a high mortality. Acute respiratory distress syndrome (ARDS) is usually considered as a severe stage of ALI. At present, the treatment of ALI/ARDS is mainly positive end-of-breath pressure ventilation, but this method still needs to be optimized to improve survival rate. Mesenchymal stem cell therapy, as a non-invasive, new treatment method, has achieved good results in animal experiments, and details of stem cell therapy in clinical practice are under investigation. Therefore, the research on the mechanism of stem cell treatment for ALI will lay a foundation for clinical treatment.