Paraquat (PQ) is a highly effective herbicide with contact toxicity. PQ mainly accumulates in the lungs after absorption into the blood circulation. The respiratory function failure caused by PQ-induced lung injury, especially the irreversible pulmonary fibrosis in late phase, is the leading cause of death in patients with PQ poisoning. The mechanism of PQ poisoning is still unclear. Now it is speculated that oxidative stress and inflammation injury are the main pathogenic mechanisms, and abnormal gene expression, mitochondrial damage, loss of pulmonary surfactant, cytokine network and unbalanced matrix metalloproteinases/tissue inhibitors may be also involved in the pathogenesis. In addition to reducing poison absorption and increasing its removal, the current clinical treatment is mainly composed of antioxidant and anti-immune response, but has poor therapeutic effects. Although many novel methods of treatment have been proposed, most of them are still in the experimental stage. It is a hot spot to clarify the mechanism of PQ poisoning and to seek safe and effective treatment of pulmonary fibrosis. This article reviews the research progress on pathogenesis and treatment of PQ-induced pulmonary fibrosis.