If lung cancer in situ is not operated for a lifetime, it is probable that it will develop into advanced stage, which will seriously jeopardize patients’ life, and it is suggested that patients should actively treat it. Lung cancer is a common malignant tumor of the respiratory system, which can be caused by smoking, gene mutation and other factors. Carcinoma in situ is the cancer cells on the alveolar epithelium, with limited lesions and relatively mild condition. Radical surgical resection, such as wedge resection, is mostly feasible in this period. After treatment, survival is basically not affected and the prognosis is very good. However, if surgery is not performed, the extent of tumor invasion will become more and more extensive, and ultimately distant metastasis will occur, resulting in extremely serious conditions, and the five-year survival rate can be less than 5%, which seriously affects the quality of life. Therefore, after diagnosis, patients should actively cooperate with doctors for treatment in order to obtain a better prognosis and prolong the survival period.