Cancer is a malignant tumor. Diagnosis of cancer needs to be confirmed by medical history, symptoms, signs and auxiliary examinations, among which there are more auxiliary examinations. Firstly, the diagnosis of cancer form requires imaging examination, which includes CT, MRI and so on. Secondly, pathological examination is needed to determine the nature of the tumor by taking biopsies and finally confirm the cancer diagnosis. Some cancers are diagnosed by blood biology examination, for example, liver cancer can be diagnosed by testing the value of methemoglobin. Malignant tumor is the abnormal proliferation of a certain tissue or organ in the body. For cancer diagnosis, comprehensive examination is needed, both morphological and pathological diagnosis should be done, plus the early clinical manifestations of cancer are not typical, many abnormalities are found during physical examination and then further diagnosis is made.