Poor lung function in esophageal cancer patients may be caused by spreading of cancer cells or infection or damage of immune system, so timely anti-tumor treatment and immune enhancement are needed. Meanwhile, malnutrition may also cause poor lung function, so it is necessary to supplement nutrition. 1. Anti-tumor: if the esophageal cancer tumor has distant metastasis or spread, it may cause infiltration of cancer cells in the lungs. At this time, it is necessary to carry out surgical resection for the primary lesion of esophageal cancer and cooperate with radiotherapy to kill the metastatic cancer cells, which can effectively protect the lung tissues and thus improve the symptoms of poor lung function. 2. Immunity enhancement: as cancer cells will cause different degrees of immune function damage and decline during the growth process in the body, thus it may cause poor function or decline symptoms of lung tissues, at this time, one can choose to take immunity enhancement drugs for immune protection under the guidance of doctor, such as gammaglobulin. 3. Supplementation of nutrition: as patients with esophageal cancer have great pain in swallowing and eating, they may not be able to take enough nutrition in daily life, which may affect the lung function and lung ventilation. At this time, the nutritional demand can be satisfied by supplementing nutritional liquid. After esophageal cancer patients have poor lung function, they should choose appropriate medicines under the guidance of doctors, and also need to do daily exercise to improve lung function.