Head and neck squamous cell carcinoma poses grave challenges to clinicians and patients due to its tumour invasiveness and treatment uncertainties. Despite the substantial improvements in conventional treatment modalities such as surgery, chemotherapy and radiotherapy, the recurrence rate and mortality rate of HNSCC remain stubbornly high. Traditionally, the front-line therapy for recurrent/metastatic HNSCC has been the amalgamation of platinum-based drugs/paclitaxel, 5-fluorouracil and cetuximab, yet it only improves the prognosis of some patients, and the overall treatment situation remains severe. Immunotherapy, as an emerging luminary in the domain of cancer treatment, is committed to improving the tumour microenvironment and stimulating the immune system to perform anti-tumour functions. The continuous updates of immune checkpoint inhibitors have also obtained favourable clinical feedback and are expected to overcome the constraints of traditional therapies. This article elaborates on the trends of immunotherapy within the TME and the progress of immunotherapy, aiming to provide new ideas for treatment regimens in the new therapeutic landscape of HNSCC and offer new hope for patients.