Pancreatectomy, especially pancreaticoduodenectomy, is the most complicated surgical approach in all abdominal surgeries. Postoperative pancreatic fistula (POPF) is the most serious complication after pancreaticoduodenectomy. Once it occurs, it will affect postoperative recovery, increase abdominal infection, and even lead to postoperative hemorrhage and life-threatening conditions. The quality of pancreaticojejunostomy has an inevitable relationship with postoperative pancreatic fistula. At present, there are many studies based on the risk factors for pancreatic fistula, including the texture of the pancreas, the diameter of the pancreatic duct, the patient's general condition and other factors, but little attention has been given to the position of the pancreatic duct in the residual pancreatic section. At present, the choice of pancreaticojejunostomy is more arbitrary. Although duct-to-mucosa pancreaticojejunostomy has become mainstream, there are still great differences. At present, there is no pancreaticojejunostomy that can completely avoid the occurrence of pancreatic fistula. The investigators found that the anatomical position of the pancreatic duct in pancreatic section was very important in pancreaticoduodenectomy and divided them into the central type and eccentric type. It was initially found that the incidence of pancreatic fistula after an eccentric pancreatic duct was significantly increased. It was confirmed that the anatomical position of the pancreatic duct is related to the occurrence of POPF. On this basis, the investigators proposed that different types of pancreatic ducts using different anastomosis methods, which may reduce the incidence of POPF. The study data come from the Department of Pancreatic Surgery, West China Hospital, Sichuan University, and the sample size is estimated from the number of patients admitted to the Department of Pancreatic Surgery in the past two years according to the POPF rate. The participants were randomly divided into the experimental group and the control group. The experimental group underwent intraoperative measurements (A: short distance from the center of the pancreatic duct to the edge of the pancreas) and (B: pancreatic thickness). When the ratio of the thickness of the short distance from the center of the pancreatic duct to the edge of the pancreas at the pancreatic section was ≥0.401, it was divided into the N1 group (central pancreatic duct). If the ratio was \<0.401, it was divided into the N2 group (eccentric pancreatic duct). The "central pancreatic duct" group was given "1+1 mode" pancreaticojejunostomy; the "eccentric pancreatic duct" group was given "1+1² mode" pancreaticojejunostomy. The patients in the control group were given "traditional pancreaticojejunostomy". The preoperative basic conditions and postoperative clinically relevant pancreatic fistula and other complications were compared between the two groups. This is expected to be confirmed by the investigators basing on the different types of pancreatic ducts, and the corresponding pancreaticojejunostomy can reduce the incidence of postoperative pancreatic fistula in patients undergoing pancreaticoduodenectomy. The primary outcome was the rate of POPF, and the secondary outcomes included postoperative hemorrhage, postoperative biliary fistula, delayed gastric emptying and so on. Preoperative baseline characteristic data were collected, including age, sex, BMI, ASA, preoperative serum protein level, preoperative blood total bilirubin level, and so on. The postoperative complications and recovery data were collected.