Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are characterized by the destruction of the barrier function of alveolar epithelial cells and capillary endothelial cells and the recruitment of inflammatory cells, which leads to alveolar and interstitial edema, hyaline membrane formation and inflammatory infiltration of the lungs, etc. The mechanism is not completely defined. The current treatment plan focuses on comprehensive treatments such as ventilator support treatment, fluid management, and nutritional support, but the prognosis is still poor. Studies have shown that extracellular vesicle microRNA (miRNA) from different sources participate in regulating the function of epithelial cells, endothelial cells and phagocytes in different ways, thus aggravating or improving ALI, and have diagnostic, differential diagnosis and the therapeutic value. In this article, the mechanism, diagnostic and differerntial value of extracellular vesicle miRNA from different sources in ALI and the therapy of extracellular vesicle miRNA from stem cell in ALI are reviewed.