This study was a single-center, single-arm, open-label phase II clinical trial. Thirty patients with unresectable locally advanced or postoperative recurrent esophageal squamous cell carcinoma were treated with concurrent chemoradiotherapy combined with immunotherapy. The radiotherapy regimen was intensity-modulated radiotherapy with PGTV at 50-50.4 Gy/25-28 fractions, 1.8-2 Gy per fraction, five times a week. The chemotherapy regimen was paclitaxel 50 mg/m2 and cisplatin 25 mg/m2 intravenous infusion on day 1, once a week for five times. The immunotherapy was with adebutilimab at 20 mg/kg on day 1, every three weeks for three times. One week before radiotherapy, gastroscopy, chest CT or PET-CT images were taken as the baseline standard. Based on the results of gastroscopy, chest CT or PET-CT before and after treatment, the number of patients with complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) in the two groups was observed. The objective response rate (ORR) was calculated as CR + PR, and the disease control rate (DCR) was calculated as CR + PR + SD. The progression-free survival (PFS), overall survival (OS), 1-year and 2-year survival rates and adverse reactions were also statistically analyzed.