Superior vena cava syndrome is the most common emergency in tumor clinic, which is mainly caused by the compression of superior vena cava by intrathoracic tumor with acute or subacute dyspnea and swelling of face and neck, and with the further aggravation of the condition, it may even appear edema of upper limbs, anguish of superficial veins above the chest like earthworms, facial petechial hemorrhage, conjunctival edema, headache, visual blurring, and impaired consciousness. Among the causes of superior vena cava syndrome, malignant tumors account for 78%-89%, with lung cancer and malignant lymphoma being the most common. Among lung cancers, small cell lung cancer is the most common, followed by squamous carcinoma. The diagnosis of superior vena cava syndrome is not difficult due to typical clinical manifestations and imaging examinations. However, due to the lack of patients’ or doctors’ awareness of superior vena cava syndrome, it is often disregarded. Superior vena cava syndrome belongs to the category of oncologic emergencies. If timely and reasonable treatment can be provided, the patient can turn out to be safe, otherwise, his life will be threatened. Our department sees many patients with superior vena cava syndrome, often admitted as emergencies. The first step of treatment is to relieve the symptoms first, and the second step is to eradicate the tumor. The patient’s head is elevated in bed and oxygen is given, medications are given intravenously from the lower extremities, hormones and diuretics are given, and sodium intake is restricted. After the first step of treatment, the condition of most of the patients is stabilized and under control. After the first step of treatment, most patients are stabilized and under control. The second step of treatment is immediately followed by radiotherapy or chemotherapy, depending on the condition of the patient. We believe that the preferred chemotherapy is highly maneuverable, without the limitation of time and equipment, and can avoid the temporary edema caused by the beginning of radiation therapy, which leads to a transient aggravation of the disease. Chemotherapy should be a fast-acting cyclic non-specific agent and the dose should be high. It is best to give hormones at the same time to minimize the reaction. Almost all patients with superior vena cava syndrome, who are first seen in a general hospital, come to our hospital after a few weeks and realize the seriousness of the disease through our explanations. It is our timely and reasonable treatment that takes the patient out of danger, creates conditions for future treatment, and gives the patient hope for life.