Clinical disease pseudocyst is relative to the true cyst, the so-called pseudocyst is no real cyst wall, because of the accumulation of seepage inside the abdominal cavity, is wrapped by the surrounding tissue to form the wrapped effusion. The most common clinical condition in which pseudocysts occur is acute severe necrotizing pancreatitis, because of pancreatic necrosis, pancreatic fistula, followed by the development of encapsulated fluid in the left upper abdomen, known as pancreatic pseudocysts. Generally speaking, pancreatic pseudocysts are mainly treated conservatively by fasting, acid production and enzyme inhibition in the early stage, and if the diameter is still over 6cm for more than 3 months, or if there are symptoms of incomplete obstruction of the gastrointestinal tract caused by compression of the gastrointestinal tract, it is usually necessary to use further surgical treatment. Pancreatic cysts are called pseudocysts because they are not surrounded by a cystic wall.