The patient was a 30-year-old male with severe acute pancreatitis and peripancreatic necrosis infection, who was treated with multiple punctures and pus extraction in an outside hospital for 4 months (without duct drainage), but still had fever and was transferred to our hospital. On admission: temperature 39℃, heart rate 100 times/min, blood pressure 120/70mmHg, respiration 18 times/min, no yellowing of the skin and sclera, epigastric tenderness, no rebound pain and myalgias, liver and spleen not detected under the ribs, negative mobile turbid sounds. Abdominal CT (Figure 1): pancreatic necrosis secondary to infection. Figure 1. CT scan of the abdomen (intravenous phase) Treatment: All tests were completed, and retroperitoneal access laparoscopic (retroperitoneoscopic) removal of pancreatic necrosis was performed under general anesthesia. The pneumoperitoneum was established and the Trocar was placed as shown in Figure 2; after the establishment of the pneumoperitoneum, the pus cavity formed by the necrotic fluid of the pancreas could be seen by gradually separating the pneumoperitoneum along the anterior renal fascia inward and upward into the pararenal space with an ultrasonic knife; the pus cavity formed by the necrotic fluid of the pancreas was removed with a noninvasive forceps and suction. In order to accurately enter the pus cavity and avoid serious bleeding caused by damage to large blood vessels, lumpectomy ultrasound technique was applied to guide the direction of surgical freeing on the one hand, and to assist in avoiding large adjacent blood vessels such as splenic vessels on the other hand; three triple-lumen silicone drainage tubes were left in place after surgery. Two weeks after the operation, because the review of abdominal CT showed that there were still residual necrotic tissues and poor drainage of fluid, the pancreatic necrosis removal was performed again along the original surgical approach and the drainage tube was re-installed. Both operations were completed successfully without surgical complications. The patient was discharged 37 days after the second operation. As shown in Figure 4, the peripancreatic necrotic effusion was significantly relieved on repeat CT before removal of the drainage tube. Figure 2. Trocar location