1. Tumor markers such as CA19-9 can be used as a means of screening, or regular screening for high-risk groups. Although these tumor markers have a certain positive rate for pancreatic cancer, they cannot be used as a basis for diagnosis because CA19-9 is also elevated to varying degrees in pancreatitis, cholecystitis, cholestatic cholangitis, liver cirrhosis, hepatitis, etc. CA19-9 examination should be combined with imaging examination. 2, abdominal CT, especially pancreatic thin layer CT scan, is the most common examination means used by clinicians at present. Enhanced CT must be done to diagnose pancreatic tumor, otherwise it is impossible to determine the invasion of surrounding blood vessels and lymph node metastasis. 3.Magnetic resonance (MR), especially MRCP, has high diagnostic value for patients with pancreatic head cancer with bile and pancreatic duct dilatation. 4.PET/CT, which has higher sensitivity and specificity for solid malignant tumors and can also show metastatic lesions, with the disadvantage that it is expensive. 5.Ultrasound endoscopy, which sends the ultrasound probe into the stomach and duodenum for detection, avoiding the interference of ultrasound by fatty tissue in the abdominal wall and gas in the gastrointestinal cavity, thus has higher resolution and can detect early pancreatic cancer, including pancreatic carcinoma in situ. Moreover, for inoperable progressive pancreatic cancer, ultrasound endoscopy-guided fine-needle aspiration is currently the main means to obtain pathology.