Generally, there is 1 drainage bag for each pancreatic pseudocyst after external drainage. Pancreatic pseudocysts can be improved by external drainage surgery, which requires abdominal exploration of the number and size of the cysts during surgery, then puncture of the cysts to clarify the nature of the cysts and to exclude intracystic hemorrhage and pseudoaneurysm, and then placing a drainage tube from the lateral abdominal wall after the surgery is completed, and generally each cyst requires only one drainage bag. Pancreatic pseudocysts are mostly secondary to acute and chronic pancreatitis or pancreatic injury, and are formed by the leakage of blood and pancreatic fluid and the pancreas’ own digestive function, resulting in tissue necrosis, disintegrated material and other aggregates that cannot be absorbed. After the operation, patients should actively carry out routine anti-infection treatment, supportive therapy, etc., and adequate and smooth drainage, and timely replacement of drainage bags. It is recommended to visit the appropriate department in the hospital for this kind of surgery and complete it under the guidance of the doctor.