If the high-resolution CT of the chest suggests ground-glass nodular shadows, but the boundaries are clear, most of them are benign chronic infectious diseases of the lungs, most of them have no clinical manifestations, and usually do not need drug treatment, and dynamic follow-up imaging can be done. The size and nature of the nodule and whether it is growing or not should be evaluated according to whether it is benign or malignant. If the nodule is smaller than 5mm, it is mostly benign and infectious, and does not require special treatment, and dynamic follow-up imaging is sufficient. If the nodule is between 6 and 8 mm, without clinical manifestations, it needs to be followed up by high-resolution CT of the chest once every 3 months, and does not need special drug treatment. If the shadow of the ground glass nodule is larger than 8mm, the border is unclear, and lobulation, short burr, etc., it is necessary to give further enhanced CT examination of the chest, and if necessary, give percutaneous lung puncture histocytology, in order to find out whether lung cancer occurs as early as possible. In conclusion, if the boundaries of the ground glass nodule are clearer, it is mostly a benign change, and it is enough to observe whether its size changes or not.