The principle of paraquat’s harm has not been fully elucidated and is currently thought to be related to the production of superoxide anion radicals. Paraquat is an electron acceptor that, when ingested by cells, acts on the intracellular oxidation-reduction reaction process, leading to the production of O2 and hydrogen peroxide, which can cause damage to cells. The body, through the active transport mechanism, allows paraquat to enter the cells, especially lung tissues; generates superoxide anion radicals in the cells, which can oxidize intracellular reduced glutathione to oxidized glutathione, affecting cell metabolism and its functions; and triggers damage to multiple organs, such as the heart, brain, liver, lungs, and so on. The above is the main mechanism of paraquat toxicity; it may also be related to paraquat’s damage to mitochondria, epithelial cells and cell membranes. When paraquat poisoning occurs, go to the hospital or call the emergency center (120) for help, and cooperate with physicians for professional treatment.