Once pulmonary fibrosis occurs, it is a serious and obvious symptom. Once the patient develops the above condition, it is usually an irreversible type of change. Pulmonary fibrosis is a gradual decrease of lung function or even inability to breathe, and patients will have progressive dyspnea, accompanied by clinical symptoms and manifestations such as hypoxemia that is difficult to correct. It is recommended to control the partial pressure of oxygen within 40mmHg as an indication for oxygen therapy. Patients can also be treated with continuous blood purification and symptomatic treatment with hormones and other drugs, because there is no special antidote for paraquat poisoning and once pulmonary fibrosis occurs, the prognosis is not good.