The prognosis of peripheral lung cancer depends on tumor typing, tumor stage, and treatment effect. It can be as short as 3 months and as long as more than 5 years. 1. Tumor typing: this is an important reason affecting the prognosis of peripheral lung cancer. Generally, among all lung cancers, undifferentiated or small cell lung cancer has the worst prognosis among all kinds of lung cancers. Without scientific treatment, the survival time of advanced small cell lung cancer is about 3 months. 2. Tumor stage: Generally speaking, the prognosis of early peripheral lung cancer is much better than that of advanced peripheral lung cancer, for example, the median survival time of advanced non-small cell lung cancer is only eight to ten months. 3. Therapeutic effect: the prognosis of patients with active and effective treatment is relatively good, and the treatment of lung cancer mainly includes surgery, chemotherapy, targeted therapy, immunotherapy, etc. After active treatment, many early-stage lung cancers have a better prognosis. After active treatment, many early stage lung cancers are expected to survive for more than five years. Early detection, early diagnosis and early treatment are the keys to improve the prognosis of peripheral lung cancer.