In recent years, with the popularization of low-dose CT and the enhancement of residents’ health care awareness, the discovery and detection rate of early-stage lung cancer has increased significantly. More and more lung cancer patients have been diagnosed and treated at an early stage. Because of better preservation of postoperative pulmonary function and better quality of life, the application of sublobar resection is also gradually increasing. Though sublobar resection has many advantages, the cases of postoperative recurrence also increase gradually at the same time. The recurrence at the margin is one of the key point worth noting. In order to solve this problem, some scholars have conducted retrospective or prospective research, but there are differences in their views. On the other hand, it is also worth noting that not all the postoperative masses appeared on the margin indicate recurrence, and the postoperative granuloma around the cutting edge is also quite common. Therefore, the differential diagnosis of marginal granuloma and marginal recurrence after sublobar resection has important clinical significance. At present, the existing research of postoperative examination (such as PET, CT, MRI) have certain limitations.