Neoadjuvant immunochemotherapy can effectively increase the postoperative pathological complete response rate, improve the survival rate of patients, and reduce the risk of recurrence in oral squamous cell carcinoma (OSCC). Programmed death ligand-1 (PD-L1) plays a role in inhibiting the cancer-immune cycle by binding to negative regulatory factors of T cell activation such as PD-1 and B7.1. It has achieved good therapeutic effects in lung cancer, liver cancer and other cancers. Previous studies have shown that three cycles of PD-L1 inhibitors combined with chemotherapy have satisfactory efficacy and safety in locally advanced oral squamous cell carcinoma. However, during the three-cycle treatment process, due to the accumulation of drug toxicity, patients' tolerance to adverse reactions decreases, increasing the risk of serious adverse events and psychological pressure on patients. Based on this, this study aims to explore the efficacy of two cycles of avelumab (PD-L1 inhibitor) combined with chemotherapy in locally advanced oral squamous cell carcinoma, to explore whether it can achieve the same efficacy as three cycles while shortening the treatment time, reduce the risk of serious adverse events, and further verify the efficacy and safety of PD-L1 inhibitors combined with chemotherapy in the treatment of locally advanced oral squamous cell carcinoma. This study uses the postoperative pathological complete response (PCR) rate as the primary outcome indicator, and the objective response rate (ORR), major pathological response (MPR) rate, 2-year disease-free survival (EFS) rate, and 2-year and 5-year overall survival (OS) rate as secondary outcome indicators to evaluate the efficacy and long-term survival impact.