This study is a single-center, single-arm, prospective, phase II clinical trial designed to evaluate the efficacy and safety of Cidabenamine combined with Azacitidine as maintenance therapy following allogeneic peripheral blood hematopoietic stem cell transplantation in patients with high-risk peripheral T-cell lymphoma.During the screening/baseline period, informed consent will be obtained, and inclusion/exclusion criteria will be verified. The study plans to enroll 40 patients in each group. Enrolled patients will undergo demographic and medical history data collection, along with assessments including vital signs, physical examination, PET-CT, bone marrow aspiration smear, flow cytometry, lymphoid gene rearrangement, and bone marrow pathology.