Papillary thyroid cancer less than 1cm has the possibility of spreading, but the possibility of spreading is small. The main reason is that papillary thyroid cancer grows slowly, and if papillary thyroid cancer is found, most patients can be cured by timely surgical resection, so its possibility of spreading is relatively small. Papillary thyroid cancer is a relatively common type of thyroid cancer, which is less malignant among several pathological types of thyroid cancer, and metastasis appears less and later. Spread of papillary thyroid cancer less than 1 cm is rare, but not completely impossible. Therefore, when papillary thyroid cancer is diagnosed, it should be treated aggressively with surgery and treatment such as iodine 131 in order to remove as many remaining cancer cells as possible. It is suggested that patients with papillary thyroid cancer must go to regular hospitals for appropriate examination and be treated accordingly under the guidance of doctors.