Once the diagnosis of insulinoma is confirmed by the endocrinology system, its accurate localization becomes the key to treatment. Abdominal ultrasound: depends on the level of ultrasound equipment and the ultrasonographer’s reading level; abdominal CT: depends on the level of CT equipment and the surgeon’s reading level; abdominal MRI: depends on the level of MRI equipment and the surgeon’s reading level; endoscopic ultrasound: depends on the level of endoscopy and the endoscopist’s reading level; abdominal PET/CT: depends on the surgeon’s reading level Intraoperative ultrasound: depends on the experience of the surgeon and the reading level of the ultrasonographer; Measurement of insulin levels in portal vein segmental blood: depends on the accuracy of portal vein blood localization collection and the correct analysis of insulin profiles; Selective arteriography: depends on the imaging technique of the radiologist and the reading level of the surgeon; Intraoperative ultrasound: depends on the experience of the surgeon and the reading level of the ultrasonographer; Measurement of blood glucose levels after intraoperative pancreatic segmental blood flow block: depends on the experience of the surgeon and the reading level of the surgeon intraoperative palpation: depends on the experience of the surgeon and the level of the surgeon’s reading; intraoperative palpation: depends on the experience of the surgeon and the level of the surgeon’s reading. Intraoperative rapid pathology: depends on the experience and level of the pathologist. Postoperative pathology: depends on the pathologist’s immunohistochemical analysis. Strictly speaking, 1 – 10 is the real sense of localization method. The final real-time localization depends on the experience of the surgeon and his correct judgment of various imaging data and intraoperative blood glucose changes, while pathology is only a means of confirmation of its final localization and characterization. Theoretically, it is possible that no tumor can be found or left behind in every case, but in the 21st century, the chance of not finding a tumor in the resected specimen is becoming less and less, especially after we adopted the “intraoperative pancreatic segmental blood flow blocking localization method”, which effectively avoids blind resection of the pancreas and tumor left behind.