In recent years, the number of deaths due to tumors has surpassed that of cardiovascular diseases, becoming the number one killer of human deaths. Among all cancer diseases, oral cancer incidence accounts for 1.45% to 5.6% of the whole body malignant tumors, including lip cancer, gum cancer, tongue cancer, hard and soft palate cancer, jaw cancer, floor of mouth cancer and oropharyngeal cancer. Since the 5-year survival rate of oral cancer after treatment is not very high, only around 60%, it is one of the malignant tumors that seriously threaten people’s health. Although oral cancer should be easily detected at an early stage compared with cancers in other parts of the body, this is not the case. Oral cancer initially appears as epithelial proliferative hard nodules, which is often not taken seriously by patients; then the surface erosion becomes ulcer, with red surface interspersed with a few white spots, shallow in but without necrosis. The patient feels slightly uncomfortable with occasional irritating pain. This stage is also easy to be ignored and treated as a general mucosal ulcer. However, on careful palpation, the ulcer surface is rough and the edges are slightly hard with a sense of edges. If the ulcer develops further, the center of the ulcer becomes necrotic and the edges are raised in a dike or petal-like outward, or the necrosis is not significant but nodular and cauliflower-like proliferation. At this time, the patient’s symptoms are obvious and often accompanied by functional impairment, but this is not the early stage of tumor. In the past, in this case, a small amount of tissue had to be cut for biopsy, and the patient often suffered a lot of pain and could only be detected after the lesion had morphological changes. In fact, before the morphological change of cancer cells, the genetic material DNA in the cells has been changed. According to this theory, the quantitative detection of genetic material (DNA) ploidy in the nucleus through the quantitative cellular DNA analysis system to determine the physiological state and pathological changes of the cells has become a new technology to screen for early tumors. This technique has been widely used in clinical diagnosis in Europe and the United States. Because the change of cell DNA content appears earlier than the change of morphology, doctors can determine whether the cells have precancerous lesions or cancerous lesions through scientific and objective analysis based on the change of DNA content, and can intervene in the early stage of cancerous lesions. The Department of Stomatology and the Department of Pathology of Wuhu First Hospital have successfully carried out this technology. It is especially suitable for the pathology of oral cavity, especially for the detection of general pathology scraping, especially for the special detection of some high incidence tumors, such as oral leukoplakia, lichen planus and oral ulcers over 3 weeks, only a small amount of oral mucosal surface cells can be taken with a small brush under non-invasive conditions, and a pathology film can be made for pathological examination and analysis. It is less invasive, less painful and highly sensitive. This test can also be used as a physical examination for healthy people for early screening of tumors; for patients with high suspicion of tumors that cannot be confirmed by general examination, it is more important to perform fully automated quantitative cellular DNA diagnosis.