• Age ≥ 18 years old.

• Previously untreated CD20-positive DLBCL patients, including the following types according to the 2016 WHO classification of lymphoid neoplasms: DLBCL, not otherwise specified (NOS) including germinal center B-cell type and activated B-cell type; T-cell/histiocyte-rich large B-cell lymphoma; Epstein - Barr virus-positive DLBCL, NOS; ALK-positive large B-cell lymphoma; HHV8-positive DLBCL, NOS; high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (double-hit or triple-hit lymphoma); high-grade B-cell lymphoma, NOS.

• Signed informed consent form (ICF).

• Eastern Cooperative Oncology Group (ECOG) performance status score 0 - 2, with an expected survival greater than 12 months.

• Have at least one measurable two-dimensional lesion determined by clinical examination, CT scan, or MRI: ① lymph nodes \> 1.5 cm; ② other non-lymph node lesions ≥ 1.0 cm.

• Good function of major organs: Hematological function: absolute neutrophil count ≥ 1,000/mm³, platelet count ≥ 75,000/mm³; Liver function: ALT/AST \< 3 times the upper limit of normal (ULN) and total bilirubin ≤ 1.5× ULN (for patients with Gilbert syndrome, hilar compressive adenopathy-induced cholestasis, liver involvement or lymphoma-induced biliary obstruction \< 5 times ULN); Renal function: creatinine clearance \> 30 mL/min, creatinine ≤ 1.5× ULN; Pulmonary function: indoor oxygen saturation ≥ 95%; Cardiac function: no obvious cardiac insufficiency or cardiovascular disease.

• Fertile patients must be willing to take highly effective contraceptive measures during the study and within 120 days after the last administration of treatment.