In the era of immunotherapy, the standard second-line treatment regimen for locally advanced/metastatic esophageal squamous cell carcinoma (ESCC) remains controversial. This prospective, single-center, single-arm phase II clinical study aims to evaluate the efficacy and safety of Ivonescimab combined with short-course hypofractionated radiotherapy as a second-line therapy for patients with locally advanced/metastatic ESCC. The study plans to enroll 37 patients who have failed first-line treatment, without grouping, all of whom will receive Ivonescimab combined with short-course hypofractionated radiotherapy. The primary endpoints are progression-free survival (PFS) and safety, while the secondary endpoints include overall survival (OS), duration of response (DOR), and objective response rate (ORR). The study duration is 2 years.