Early indicators of small cell lung cancer do not have specific manifestations, which mainly show symptoms such as loss of appetite, fatigue, hoarseness, chest pain, etc. Cough or sputum with blood in sputum may also occur, and some patients may suffer from hemoptysis, which may even directly lead to shock. Small cell lung cancer is usually centralized lung cancer, and the early indicators are not obvious, and often can only be found when patients undergo physical examination, such as chest CT examination. It is necessary to be vigilant that small cell lung cancer, as a kind of lung cancer, has a very high degree of malignancy, and the growth of cancer cells is very rapid, and once the clinical manifestations appear, the diagnosis is usually made in the middle or late stage. If small cell lung cancer has been diagnosed at an early stage, effective treatment programs, such as the emerging bio-immunotherapy, should be adopted in time, and patients still have the hope of being cured. Therefore, early-stage patients should be more relaxed, face the disease positively and cooperate with the treatment, in order to get a better prognosis.