Abstract: The present disclosure provides use of malic enzyme 2 (ME2) in preparation of a diagnostic reagent or a medicament for silicosis or pulmonary fibrosis-related diseases, and belongs to the technical fields of medical treatment and medicine. Research results of the present disclosure show that ME2 knockout significantly alleviates inflammatory response and fibrotic lesions in mice with silicosis. Based on the above research results, the present disclosure provides use of ME2 in treatment of pulmonary inflammatory responses and pulmonary fibrotic lesions of silicosis or pulmonary fibrosis-related diseases. Expression of ME2 is inhibited to alleviate the inflammatory response and fibrotic lesions of the silicosis, providing support for exploring a targeted drug for treating pulmonary inflammatory responses and pulmonary fibrosis of silicosis or pulmonary fibrosis-related diseases.