• Age: ≥18 years old and gender-neutral;

• Follicular lymphoma definitively diagnosed according to the REAL/WHO classification, stage II-IV requiring treatment according to the GELF code;

• ECOG score 0-2;

• Lymphoma efficacy evaluation criteria using Lugano 2014 Lymphoma must have at least one measurable or evaluable lesion: signed informed consent, subjects recruited based on inclusion and exclusion criteria, etc History taking and pre-treatment baseline examination and registration on case report form (CRF) ZO regimen of chemotherapy for 6 cycles, followed by zebrutinib monotherapy orally for 6 months, with observation of toxicities Follow-up assessment (including) Follow-up evaluation (including safety) \<Blood, biochemistry, B2-MG, neck, chest and abdomen CT plain + enhanced, questionnaire\> Follow-up evaluation (including safety) \<Blood, biochemistry, B2-MG, neck, chest and abdomen CT plain + enhanced, questionnaire, once every three months\> 1. Zerbutinib maintenance treatment for 12 months for PR and above 2. Second-line treatment for the rest of the patients (recommended by NCCN guidelines) NCCN guideline recommendation) Assessment of efficacy i.e. PET/CT with evaluable lesions; CT or MR evaluation of intranodal lesions with a long diameter \>1.5cm, short diameter \>1.0cm or extranodal lesions with a long diameter \>1.0cm;

• HBV-positive serology (concealed carriers: anti-HBeAg +, HbsAg-, anti-HBsAg +/-) Enrollment only if HBV-DNA test is negative;

• Normal major organ function: liver function serum bilirubin ≤ 2.0 × ULN , serum ALT and AST ≤ 2.5 × ULN, renal function: serum Cr ≤ 2.0 × ULN; (unless due to lymphoma);

• Informed consent (patients must sign an informed consent form for all studies).