Combination antiviral therapy of nucleos(t)ide analogue (NA) and pegylated interferon alpha (peg-IFN alpha) decrease hepatitis B virus (HBV) surface antigen (HBsAg) levels to achieve functional cure and improve long-term prognosis in chronic hepatitis B patients. However, for hepatitis B-related liver fibrosis, studies on combination of these two medicines are limited. This study was designed to compare the efficacy between peg-IFN alpha combined with tenofovir (TDF) and TDF monotherapy for the clearance of HBsAg in NA-experienced patients with HBV-related liver fibrosis.This study was designed to be a prospective, multicentre, open, randomised controlled study. A total of 272 patients with HBV-related liver fibrosis will be randomised into the combination therapy group or the monotherapy group at a 1:1 ratio. Participants in the combination group will receive subcutaneous injections of peg-IFN alpha 180 µg per week for 48 weeks combined with oral TDF 300 mg daily. Participants in the monotherapy group will receive 300 mg oral TDF daily alone. All participants will undergo long-term treatment with TDF and will be followed up at the outpatient department for 144 weeks after randomisation. Clinical symptoms, laboratory tests and examination indicators will be collected at each follow-up time point, and adverse events will be recorded. The primary endpoint is serological clearance rate of HBsAg at 48 weeks.The ethics committee of the Third Affiliated Hospital at Sun Yat-sen University approved this study (Approval Number: (2020)02-183-01). The results of the study will be presented at relevant meetings and published in an appropriate journal after the completion of the trial and the analysis of the data.NCT04640129.© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.