Pulmonary nodules are actually a relatively common lung disease at present. Nodules can occur either singly or in multiple cases, and according to reports, the probability of lung cancer occurring in lung nodules is about 40%. Lung nodules are not equal to lung cancer. Small nodules in the lung can occur in many areas, like benign inflammation, tuberculosis, etc. For patients with small nodules in the lung on initial investigation, the nature of the nodules should be clarified first. The malignancy rate of small nodules less than 2cm is relatively low. We should review the chest X-ray regularly and observe the changes of nodules in size at 3 months, 6 months, 1 year and 2 years.