Inclusion Criteria:
* Signing informed consent; ECOG 0-2 points;
* Age over 18 years old, gender is not limited;
* Esophageal squamous cell carcinoma confirmed by pathology or clinically diagnosed by imaging;
* Recurrence of the tumor area after radical surgery or radical chemoradiotherapy; Regional progression of advanced esophageal squamous cell carcinoma after first-line or second-line treatment;
* Clinical staging: regional recurrence (rT0-4N0-3M0-1a) or regional progression (cT0-4N0-3M0-1) (AJCC/UICC esophageal cancer staging (8th edition));
* Tumor lesions can be evaluated;
* Expected survival ≥3 months;
* Major organ function is normal, meeting the following criteria: (i) blood routine examination A.HB ≥90g/L; b.ANC≥1.5×109/L; C. PLT ≥80×109/L; (ii) Biochemical examination: a. ALT/AST≤2.5ULN; b. TBIL≤1.5ULN; c. Plasma Cr≤1.5ULN or creatinine clearance (CCr)≥60ml/min;
* Women of childbearing age must have had a pregnancy within 7 days before starting treatment and the result is negative;
* All enrolled patients should take adequate contraceptive measures throughout the treatment period and 4 weeks after completion;
* no serious hematopoietic function, heart function, endocrine and immune function defects;
* No patients with grade 3 or above other serious medical diseases.
Exclusion Criteria:
* Under 18 years of age; ECOG is greater than 2;
* The diagnosis of esophageal cancer is not supported by pathological biopsy or image examination;
* Salvage surgery was performed after tumor recurrence;
* The patient has any active autoimmune disease (such as the following, but not limited to: autoimmune hepatitis, interstitial pneumonia, uveitis, enteritis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism; The patient had vitiligo; Those with complete remission of asthma in childhood can be included without any intervention in adulthood; Patients with asthma requiring medical intervention with bronchodilators are not included);
* Patients who were taking immunosuppressants or systemic hormone therapy for immunosuppressive purposes (doses \>10mg/ day of prednisone or other therapeutic hormones) and continued to use within 2 weeks before enrollment;
* Patients with severe and/or uncontrolled concomitant disease of grade 3 or higher, including: poor blood pressure control, myocardial ischemia or myocardial infarction, arrhythmia, active or uncontrolled severe infection; Liver diseases such as decompensated liver disease, active hepatitis B (HBV-DNA≥104 copy numbers /ml or 2000IU/ml), or hepatitis C (hepatitis C antibody positive and HCV-RNA above the lower detection limit of analytical methods);
* Pregnant or lactating women;
* Patients who have a history of psychotropic drug abuse and cannot quit or have mental disorders;
* Patients who have participated in clinical trials of other drugs within four weeks; .Patients or family members refused to participate in the study.
