The splenic vein belongs to the portal venous system and usually flows into the liver after joining with the superior mesenteric vein and the inferior mesenteric vein. Dilatation of the splenic vein refers to the obstruction of blood return and pressure in the splenic vein, which causes blood stagnation in the splenic vein vessels and an increase in the width of the splenic vein. The common clinical causes of splenic vein dilatation are as follows: i. Hepatitis B cirrhosis is often accompanied by hardening of the liver, obstruction of portal vein blood return, resulting in portal hypertension, which may cause tortuous and dilated splenic vein. Cirrhosis severe patients may even cause hypersplenism, resulting in the destruction of blood cells. Second, patients with malignant tumor of pancreas, due to the tumor compression to the splenic vein, will also cause the obstruction of blood return to the splenic vein, a large number of splenic vein stagnation, splenic vein dilatation. At this time, patients need to perform surgery as soon as possible to remove the malignant tumor of pancreas in order to relieve the pressure on the splenic vein and improve the symptoms of tortuous and dilated splenic vein.