The purpose of this randomized Phase II study is to evaluate and compare the efficacy and safety of neoadjuvant radio-immunotherapy versus immunotherapy alone for patients with locally advanced head and neck squamous cell carcinoma (HNSCC). Participants will be randomly assigned to one of two groups. The experimental group will receive a combination of radiotherapy and Adebrelimab as neoadjuvant treatment, while the control group will receive Adebrelimab monotherapy. Following the neoadjuvant phase, all eligible patients will undergo surgical resection. The primary objective is to determine if the addition of radiotherapy improves the major pathological response (MPR) rate. Secondary objectives include pathological complete response (pCR) rate, objective response rate (ORR), and event-free survival (EFS).