This study is a prospective, single-arm, single-center Phase Ib clinical trial of Becotatug Vedotin in combination with cisplatin and concurrent radiotherapy for locally advanced esophageal squamous cell carcinoma. The primary objectives are to investigate the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and recommended Phase II dose (RP2D) of Becotatug Vedotin in combination with cisplatin and concurrent radiotherapy for locally advanced esophageal squamous cell carcinoma. The secondary objectives are to assess the efficacy and safety of this combination regimen.