Abstract: Richter syndrome (RS) is a rare disease of the lymphohematopoietic system. It is defined as the transformation of a low-grade malignant lymphoproliferative disorder into a more aggressive lymphoproliferative disorder, most commonly, diffuse large B-cell lymphoma (DLBCL). The disease is rare in the clinic and has nonspecific clinical manifestations. An excisional lymph node biopsy is considered the gold standard for diagnosis of RS; ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) can help inform the optimal site for biopsy. The main treatment strategies are chemotherapy, hematopoietic stem cell transplantation (HSCT), participating in a clinical trial of a new medicine, and others, but the overall prognosis is poor. At present, there is no sufficient treatment for the disease. In order to improve the awareness of disease and identify it among a variety of similar diseases, while aiming to discuss treatment strategies, this article reviewed RS in terms of the risk factors, clinical manifestations, diagnosis, treatment, and prognosis.