Adenocarcinoma in situ of the lung is a major disease. Adenocarcinoma in situ of the lung is early stage lung adenocarcinoma, adenocarcinoma is a pathological type of lung cancer, as long as it is a malignant tumor should belong to major diseases. However, compared with other malignant tumors of the lung, adenocarcinoma in situ is relatively limited, only confined to the bronchopulmonary mucosa layer, and does not have infiltration of the surrounding tissues or lymphatic or hematogenous metastasis, so the treatment effect is relatively good. Once adenocarcinoma in situ is detected, it should be surgically resected as early as possible, and after surgical resection, it can basically be clinically cured, and patients often do not need to undergo further chemotherapy and radiotherapy after surgery. Although early treatment of adenocarcinoma in situ has better effect and the probability of recurrence is relatively small, patients still need to cooperate with doctors for regular review.