Portal vein thrombosis is a common complication in patients with cirrhosis. Currently, there are about 20 million patients with chronic hepatitis B in China, of which nearly 25-30% of chronic hepatitis B patients can develop cirrhosis. The liver receives 3/4 of its blood from the portal vein, which drains blood from the intestines, and the blood drained from the intestines is filled with digested food to be processed by the liver. After cirrhosis, due to the slowing down of hepatic blood flow in the portal vein, it is extremely easy to cause portal vein thrombosis, which can lead to life-threatening intestinal necrosis due to portal vein blockage in severe cases. Portal vein thrombosis is particularly common in patients with a history of surgical intervention for portal hypertension, which in mild cases mainly manifests as abdominal distention, blood in the stool, abdominal pain, and back pain. If the main trunk of the portal vein or even the superior mesenteric vein is completely embolized, it may lead to serious consequences such as liver failure, refractory ascites, blood in the stool, intestinal obstruction, and even intestinal bruising and necrosis. I had admitted a 48-year-old woman with post-hepatitis cirrhosis for 15 years who had inexplicable stomach pain for 1 day. After examination, the portal vein and superior mesenteric vein were found to be blocked by thrombus, and we performed emergency surgical treatment, during which it was found that the portal vein thrombus had led to intestinal necrosis, and eventually nearly 1 meter of necrotic small intestine was removed. Without timely surgery, the condition would have been life-threatening if it had not progressed.