Abstract: Secondary central nervous system diffuse large B-cell lymphoma (DLBCL) is a serious clinical complication with limited treatment options and a generally poor prognosis. With the widespread use of rituximab, its incidence has tended to decrease, and brain parenchymal involvement is becoming more common. The importance of pathological biopsy in diagnosis is increasing. The identification of high-risk factors requires a comprehensive evaluation of clinical and molecular biological factors. Although systemic chemotherapy with high-dose methotrexate is the mainstay of prophylaxis, its role in treatment is controversial. The therapeutic value of new drugs and therapies, such as ibrutinib, needs to be explored further. This review summarizes the progress in the diagnosis and treatment of secondary central nervous system DLBCL in recent years.