The first line of chemotherapy regimen for aggressive diffuse large B lymphoma is the R-CHOP regimen, which has strong sensitivity to diffuse large B lymphoma, but the toxic side effects, drug resistance and recurrence of chemotherapy should not be ignored. Diffuse large B lymphoma is an aggressive lymphoid malignancy that must be treated as soon as possible after diagnosis. Its treatment paradigm is a multidisciplinary combination of mainly medical therapy, which requires the selection of appropriate regimens based on the patient’s age, Ann Arbor staging and international prognostic indices, as well as the immune and molecular phenotypic characteristics of the tumor. A common chemotherapy regimen is the R-CHOP regimen, i.e., rituximab + cyclophosphamide + doxorubicin + vincristine + prednisolone: a cycle of 21 days is usually given, and the standard of care is usually 6-8 courses of treatment, depending on the tumor stage. Rituximab has a significant therapeutic effect on CD20-positive patients with relapsed refractory diffuse large B lymphoma. For patients who are elderly or not suitable for standard chemotherapy, R-GemOx, R-miniCHOP, R-CDOP, R-CEPP, R-GCVP, etc. or targeted therapy-based regimens can be considered. During the treatment period, patients should be aware of the adverse reactions, some patients may have anemia, venous pathway pain and swelling, nausea and vomiting, etc., try to find out early and deal with it as early as possible, so as to avoid a more serious situation.