Diffuse large B-cell lymphoma may recur in 2/3 of patients. The cure of diffuse large B-cell lymphoma cannot be separated from its staging, so the patients must cooperate with the competent doctor to do staging examination in the early stage, including CT of the neck, chest, abdomen and pelvis, whole body ultrasound, bone marrow aspiration examination, and brain enhancement magnetic resonance and PET-CT if there are conditions.After the relapse, the teacher of the Department of Pathology asks to do some tests like CT5, whether there is EBV, whether there is P53, whether there is C-MYC gene, whether there is high expression of BCL-2 and BCL-6, etc. to judge whether it is a double-battered or triple-battered patient. MYC gene, high expression of BCL-2 and BCL-6, etc., to determine whether the patient is a double or triple hit patient. If the patient is a double or triple hit patient, or has double expression of large B-cell lymphoma, its prognosis is poorer. If the conventional chemotherapy regimen is ineffective, it is necessary to intervene at an early stage to treat it with a double R regimen, or even to intervene earlier with stem cell transplantation.