At present, lung cancer is clinically categorized into non-small cell lung cancer and small cell lung cancer. Small cell lung cancer is a type of lung cancer with high malignancy, short multiplication time, poor prognosis and high mortality rate. Common complications of small cell lung cancer include the following: 1) superior vena cava obstruction syndrome, caused by lung cancer compression, patients show swelling of face and neck, dyspnea, etc. 2) hyponatremia, also a common clinical manifestation of small cell lung cancer, patients show apathy, decreased responsiveness, and other clinical manifestations. 3) paraneoplastic syndrome clinical manifestations, patients mainly show antidiuretic hormone secretion Abnormal syndrome, Cushing’s syndrome, cerebellar degeneration syndrome and myasthenia gravis syndrome.4. Acute tumor lysis syndrome after small-cell lung cancer treatment, in which patients show hyperuricemia, hyperkalemia, hypocalcemia and so on.