Acute pulmonary embolism is a clinically acute and critical condition that can cause high rates of death and disability. The clinical syndrome caused by various emboli obstructing the pulmonary artery or its branches is called pulmonary embolism. Due to the different components of emboli, it can be divided into pulmonary thromboembolism, fat embolism syndrome, amniotic fluid embolism, air embolism, tumor embolism and so on. Among them, pulmonary thromboembolism is the most common, accounting for more than 90% of pulmonary embolism. And most of the thrombi in pulmonary embolism come from the deep vein thrombosis of the lower extremities. The risk factors of acute pulmonary embolism mainly include surgery, trauma, pregnancy and perinatal period, malignant tumor, myocardial infarction, varicose veins and so on. People with the above high-risk factors, when the thrombus dislodges into the pulmonary artery, causing the blockage of pulmonary vascular blood flow, can also cause the constriction of pulmonary vessels, and finally cause the increase of pulmonary vascular resistance. It causes a series of pathophysiological changes, with dyspnea, chest pain, hemoptysis, and even syncope and other prochlorotic bed manifestations. It should be noted that some patients have no obvious clinical manifestations or have non-specific manifestations such as weakness and decreased activity endurance. The diagnosis mainly relies on medical history, clinical manifestations and auxiliary examinations. Among the ancillary examinations are blood gas analysis, D-dimer test, and CTPA of pulmonary artery. Once the diagnosis of pulmonary embolism is made, different comprehensive treatments are needed according to different conditions, mainly including anticoagulation, correction of heart failure and improvement of lung function.