Postoperative hypertension can be caused by the following reasons: 1) pain: stress hypertension, which can be relieved by giving analgesic and sedative drugs; 2) intolerance of tracheal intubation: it cannot be treated by extubation, but analgesic and sedative drugs can also be applied to relieve it; 3) elevated blood volume: it is caused by large amount of intraoperative bleeding, large amount of rehydration, volume expansion and blood transfusion; 4) history of preoperative hypertension: it can be relieved by oral antihypertensive drugs. Therefore, for patients with postoperative hypertensive manifestations, symptomatic treatment combined with their specific causes of occurrence is required to avoid loss of treatment and mismanagement.