B-cell lymphomas include Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL), diffuse large b-cell lymphoma (DLBCL) is a type of NHL, and primary CNS diffuse large b-lymphoma is a less common form of DLBCL that occurs in the central nervous system. Primary CNS diffuse large b lymphoma has common characteristics of DLBCL. It is a malignant tumor formed by diffuse proliferation of moderately large B lymphocytes, and the tumor cells express B cell-associated markers such as CD20, Pax-5, OCT-2, and Bob-1, and have a high Ki-67 index, which makes them more aggressive. As a special subtype of DLBCL, primary CNS diffuse large b-cell lymphoma has its specificity. Patients are mostly men over 60 years old, and the tumor cells are centroblastic or immunoblastic, expressing germinal center B cell (GCB) markers CD10 and Bcl-6. It is recommended that all lymphoma patients actively cooperate with treatment to prolong survival and improve prognosis.