The presence of pleural effusion in advanced lung cancer can not be used as the basis for judging the survival time, it can only be said that active treatment can prolong the survival time, and if giving up the treatment, the patient will die soon. Pleural effusion is one of the more common symptoms of advanced lung cancer patients, once this situation occurs, it means that the patient’s condition is serious, but it can not be used as the basis for judging the survival time, and it needs to be analyzed in combination with the treatment situation, pathological type, clinical stage, etc., and there is no way to determine the specific time. Generally speaking, if the patient can actively take radiotherapy, chemotherapy and drainage and other treatments, it can effectively prolong its survival; if the patient abandons the treatment, the condition will continue to worsen, and death may soon occur.