Early esophageal cancer refers to tumors confined to the esophageal mucosa and submucosa without lymph node metastasis, including carcinoma in situ, intramucosal cancer and submucosal cancer. Unfortunately, the symptoms of early esophageal cancer lack specificity, and they appear and disappear, so they are easy to be ignored or even asymptomatic. The common early clinical symptoms are as follows: 1) discomfort, stuffiness, burning or pinching/pulling pain at the back of sternum when swallowing, which is especially significant when eating rough, overheated or irritating food; 2) mild choking sensation when swallowing food, commonly known as “pressurized air”, which is obvious to most of the patients when swallowing dry food in large mouths, and this symptom may disappear by itself in some patients, but if it is repeated, the symptoms may disappear by itself. This symptom may disappear by itself in some patients, but if it occurs repeatedly or worsens gradually and the frequency increases, it is necessary to be highly alert to esophageal cancer; 3. Slow passage of food or feeling of stagnation, or sensation of foreign body; 4. Dryness and tightness in the throat. The above symptoms may exist alone or at the same time, and may occur intermittently or persistently. If the above symptoms occur, we should be vigilant and consult the doctor in time. Sometimes, patients may consult the doctor with “increased sputum”, which is characterized by spitting a large amount of mucus foamy sputum, aggravated at night or when lying down, mostly without coughing. This is due to the narrowing of the lumen of the tube caused by esophageal tumors, which makes it impossible for the saliva to pass through, and then a large amount of saliva accumulates and refluxes. This symptom often suggests that the esophageal tumor has a large size and must be diagnosed and treated in time.