Abstract: Diffuse large B-cell lymphoma(DLBCL) is a common aggressive non-Hodgkin lymphoma(NHL). When rituximab combined with cyclophosphamide, doxorubicin, vincristine, and methylprednisolone chemotherapy regimen is applied, the cure rate of DLBCL patients can reach 60%-80%. However, DLBCL possesses prominent heterogeneity of molecular pathology, and different patients have different efficacies and prognoses. Therefore, the correct evaluation of efficacy and prognosis is the focus of the current study. ¹⁸F-FDG PET/CT is an imaging tool commonly used for DLBCL patients during therapeutic and prognostic evaluation. The international prognostic index(IPI) and the national comprehensive cancer network-international prognostic index (NCCN-IPI) are widely used clinical prognostic scoring systems for malignant lymphoma. Recently, the prognostic value of a number of new clinical and molecular pathological factors has been explored. This study reviews the application, research progress, and development trend of PET/CT, clinical prognostic score system, different clinical and molecular pathologic prognostic factors during treatment evaluation, and prognosis of DLBCL patients.