In the process of receiving patients, doctors mainly diagnose the disease through the following ways: 1. Detailed medical history, comprehensive physical examination, various routine tests and laboratory tests with certain specificity. For example, fetoprotein, carcinoembryonic antigen, etc. 2.Physical examination: about 75% of cancers occur in the parts of the body that are easy to find. Therefore, comprehensive physical examination, including visual examination, palpation, percussion, auscultation, etc., is very important and can often detect part of the tumor and make preliminary judgment on its nature. 3.Imaging examination: including routine X-ray fluoroscopy, radiography, various imaging, various body scans; CT, ECT, MRI, PET-CT, etc.; B-type ultrasound examination, nuclear medicine examination, etc. 4.Pathology examination: exfoliative cytology examination and biopsy. 5.Endoscopy: esophagoscopy, fiberoptic gastroscopy and fiberoptic colonoscopy, bronchoscopy, cystoscopy, etc. 6.Radioimmunological examination: such as fetal nail protein determination, carcinoembryonic antigen detection, EBV antibody detection, etc. Among them, pathological diagnosis is especially important. In addition, carrying out regional cancer prevention census is also a more valuable way for early detection. Through screening, early cancer patients can be detected, which is very important to improve the survival rate of cancer patients.