According to AJCC staging criteria lung cancer T3 means that the lesion is between 5~7cm, or invades pleura, chest wall, phrenic nerve, pericardium, or the lesion appears as a single lesion in the lung lobe. Lung cancer T3 belongs to relatively large foci, and patients often have obvious clinical symptoms, such as cough, hemoptysis, chest tightness, chest pain and so on. These patients need to undergo fine evaluation of CT to assess the relationship between the lesion and the surrounding organs, as well as the lymph node situation, to decide whether they can be treated surgically. Those who are able to undergo surgery should actively choose surgery as it is the only means of cure, and those who are not able to undergo surgery should consider other means of treatment, such as chemotherapy, radiotherapy, targeting and so on.