• Age ≥18 years, male or female not limited;

• Patients must have the capacity to understand and willingly provide written informed consent;

• ECOG score 0-3 points;

• Expected lifespan\>3 months;

• Patients with peripheral T-cell lymphoma (PTCL) confirmed by histopathology/cytology using the 2022 World Health Organization (WHO) Classification of Diseases;

• Measurable lesions with a short diameter of ≥15mm defined by PET/CT;

• R/R PTCL: patients with at least previous first-line treatment failure and no prior exposure to chidamide, lenalidomide and bendamustine;

• Any non-hematological toxicity, except hair loss, associated with prior treatment in patients with R/R disease, as per NCI CTCAE version 5.0, must be managed and resolved to at least grade 1;

• Appropriate organ function: Cardiac function: ejection fraction ≥ 50%, asymptomatic arrhythmia; Liver function: alanine aminotransferase and aspartate aminotransferase ≤ 2 times the upper limit of normal, total bilirubin\<2 times the upper limit of normal; Renal function: serum creatinine clearance rate ≥ 80 mL/min, creatinine\<160 umol/l; Pulmonary function: Without oxygen inhalation, SPO2\>90%, FEV1, FVC, and DLCO ≥ 50% predicted values;

⁃ Adequate bone marrow reserve is defined as: Hemoglobin ≥ 9g/dL, Platelet count ≥ 70 × 10 \^ 9/L, The absolute value of neutrophils is ≥ 1.0 × 10 \^ 9/L, If accompanied by bone marrow invasion, platelet count ≥ 50 × 10 \^ 9/L, absolute neutrophil count ≥ 0.75 × 10 \^ 9/L, The number of CD34+cells is ≥ 2.0 × 109/kg;

⁃ Subjects with fertility or potential for fertility must be willing to undergo contraception from the date of registration in this study until the study follow-up period;

⁃ Patients with good compliance.