Pulmonary ground glass nodules are not necessarily malignant lesions, but the likelihood of malignancy is high. Pulmonary ground glass nodules refer to focal mild hyperdensity shadow in the lung, which can be seen in a variety of diseases without clear vascular, soft tissue component and vacuolar sign. Ground glass nodules with diameter <5mm and low density are mostly benign lesions, such as focal fibrosis, inflammation, hemorrhage, etc.; ground glass nodules with diameter >8mm, higher density, or even vacuolar sign, soft tissue component and trophoblastic vessels, accompanied by obvious fluid separation, pleural traction, etc., there is a possibility of cancer or malignant lesions, such as pre-infiltrative lung adenocarcinoma, atypical adenomatous hyperplasia, adenocarcinoma in situ, metastasis, etc. Therefore, pulmonary ground glass nodules are not necessarily malignant, but the possibility of malignancy is high. Patients found to have pulmonary ground glass nodules need to be reviewed in 1-3 months and treatment will be chosen based on the results of the review.