Brain metastasis of small cell lung cancer requires local radiotherapy, systemic chemotherapy, targeted therapy and other anti-cancer treatments, as well as antihypertensive and decongestive treatments when necessary. Small cell lung cancer has a high degree of malignancy, once brain metastasis occurs, it means that the patient enters the advanced stage, first of all, radiotherapy should be carried out for the brain metastasis, such as whole-brain radiotherapy, gamma knife, x-knife, radio wave knife, etc. The next step is to carry out systemic chemotherapy to prevent brain metastasis. Secondly, systemic chemotherapy should be carried out to avoid systemic metastasis and spreading of cancer cells along with blood circulation and to better stabilize the condition; if there is gene mutation, targeted therapy can also be considered. In addition, if the patient has headache and coma, it is necessary to use acetazolamide and mannitol to reduce blood pressure and swelling, so as to alleviate the patient’s symptoms.