With the popularization and advancement of laparoscopic techniques, more and more attention has been paid to the anatomical relationship between lesions in the deep intra-abdominal organs and retroperitoneal space, which cannot be seen directly due to loss of palpation, and adjacent organs during laparoscopic surgery. The introduction of Laparoscopic ultrasonography (LUS) has added a new dimension to laparoscopic surgery, and the scope of treatment has become more extensive, covering almost all areas of open surgery. In recent years, the use of LUS for the diagnosis and staging of pancreatic cancer, the degree of tumor invasion or lymph node metastasis to make further assessment, and the selection of appropriate surgical methods to optimize the quality of life of patients before the end of life has attracted a lot of attention from scholars at home and abroad. 1. The location of the poke hole Machi, on the other hand, advocates the three-hole method, i.e., the probe is placed through the subxiphoid process, under the right rib margin, and the umbilical poke hole, and he believes that the two-hole method is difficult to achieve a comprehensive scan of the liver and pancreas at the same time [7]. Since the pancreas is a retroperitoneal organ, it is not easy to reveal, and often requires auxiliary surgical instruments to push away the gastrointestinal tract and greater omentum blocking the front of the pancreas with appropriate movements under the microscope, or to separate the gastrocolic ligament to access the lesser omental sac, and the three-hole approach facilitates the placement of auxiliary surgical instruments for revealing and separating. The scan of the head of the pancreas is best done through the subxiphoid poke, while the scan of the tail of the pancreas is better done through the right abdominal wall or umbilical poke. It is worth noting that when radical resection is estimated to be impossible and laparoscopic internal biliary drainage is proposed, the location of the poke hole should be the same as that required for four-hole laparoscopic cholecystectomy (LC). 2.Laparoscopy Cuschicri was the first to apply laparoscopic techniques to the diagnosis and clinical staging of pancreatic cancer in 1999, with the aim of detecting enlarged retroperitoneal lymph nodes and metastatic nodes in the liver and reducing unnecessary dissection.The Sban-Kettering Cancer Center uses multiport laparoscopy for the diagnosis and staging of pancreatic cancer, which is performed like dissection, first assessing the primary site, examining the liver and liver hilum The laparoscopy is performed by first evaluating the primary site, examining the liver and hilum, dissecting the omentum, examining the caudal lobe, vena cava, celiac artery and small omental sac, identifying Traitz’s ligament, and observing the colonic mesentery, duodenum and jejunum. The tumor cannot be resected until the following laparoscopic findings are determined: (1) the tumor extends outside the pancreas, such as the transverse colonic mesentery; (2) the lymph nodes of the celiac artery or portal vein have been invaded; (3) the tumor has encircled the celiac artery or hepatic artery; (4) the tumor has encircled the portal vein, superior mesenteric artery and vein. If multiple implants of the peritoneum, metastases on the surface of the liver and spleen, extensive direct invasion of the gastroduodenal or transverse colon mesentery are found, especially invasion beyond the scope of radical surgical resection, it suggests that there is no possibility of radical resection. If the laparoscopic lesion cannot be identified as a metastasis and this metastasis is outside the prescribed resection range, a biopsy should be performed microscopically.Collen et al. proposed extended laparoscopic staging to clarify the presence or absence of metastases by systematic examination of the abdominal cavity in four directions. Laparoscopic lavage of the peritoneal cavity and collection of lavage fluid for cytological examination can determine the presence of exfoliated implantation metastases of tumor cells. The positive finding of cancer cells in the lavage fluid of the abdomen indicates that the tumor is not curatively resectable. If lumpectomy is not found to be contraindicated for radical surgery, LUS examination should be performed to do further staging. 3. Intraoperative laparoscopic ultrasound scan Given that laparoscopic staging is limited by (1) two-dimensional examination only; (2) inability to finger touch; and (3) inability to correctly assess the true relationship between the tumor and retroperitoneal vessels. Machi recommends that in cases where the liver and pancreas need to be scanned simultaneously, the ultrasound probe is first placed through a poked hole in the right abdominal wall, allowing most of the hepatopancreatic scan to be done in one pass without the need for probe transposition. In general, for intraoperative laparoscopic ultrasound examination of the head of pancreas and the hooks, the probe can be placed directly on the surface of the gastrocolic ligament, or the anterolateral part of the first and second segment of the duodenum can be used as the ultrasound window for scanning. The focus of pancreatic head cancer scan is on the head of pancreas, and the purpose is to understand whether there is direct invasion of the superior mesenteric artery and inferior vena cava by the cancer, and the invasion of the superior mesenteric vessels is the most important reason for losing the chance of radical resection for pancreatic head cancer. Turning on the Doppler flow imaging switch can well show the relationship between the mass and the important large peripancreatic vessels such as portal vein, superior mesenteric vein, superior mesenteric artery, inferior vena cava and abdominal aorta. The probe should be placed from the right abdominal wall poke hole or umbilical poke hole when scanning the spleen, and the ultrasound window through the anterior wall of the stomach is more effective when examining the tail of the pancreatic body. LUS is indisputably superior in detecting microscopic metastases deep in the liver that are not detected by preoperative imaging. Once multiple metastases in the liver that were not detected by preoperative imaging are identified, there is no need to perform a pointless dissection.