Calcified shadow of pulmonary nodules refers to localized calcified foci formed by factors such as tuberculosis, infection, trauma or malignant tumors, etc. It is a calcified shadow formed by the deposition of calcium ions in the form of calcium phosphate in the destroyed lung tissues, and most of them belong to the obsolete lesions, and very few of them are deteriorated. The common clinical causes of calcified lung nodules include chronic lung infection, traumatic tuberculosis, etc. The lung lesions caused by them, after treatment or autoimmune self-healing, are a manifestation of damage repair, manifesting as localized calcified foci. If the calcified shadow of lung nodule is less than 5mm and without any discomfort symptoms, no special treatment is needed, and regular review is enough. If the nodule is larger than 6mm or even 8mm with calcification and accompanied by cough, sputum, blood in sputum, chest tightness, chest pain and other symptoms, it is necessary to further give chest enhancement CT examination, and if necessary, lung puncture biopsy in order to clarify the cause of the disease, and active etiological treatment, so as to avoid delaying the condition.