Carcinoma in situ of lung is important, it belongs to the early stage of lung cancer, and the prognosis is better if patients take treatment in time. If patients do not take timely treatment measures, it may lead to deterioration of the condition, which is critical and patients are recommended to take timely surgical treatment. Patients with carcinoma in situ of lungs, which refers to cancer cells with primary site in lungs without infiltrative growth and metastasis, are generally not important, and patients usually recover better after taking treatment measures. If the patient is not treated, invasive lung cancer or metastasis may occur, which is a critical situation. Patients with carcinoma in situ of the lung should take treatment measures in time, and they can be treated by lobectomy, extended resection, radical surgery and other surgical methods according to doctor’s instructions. When patients develop lung in situ cancer, it is recommended that they should seek medical treatment in time for early detection and early treatment. Patients should take therapeutic measures under doctor’s guidance to avoid disease progression.