Lung cancer is the malignant tumor that ranks first globally in both incidence and mortality rates. According to the latest statistics from the International Agency for Research on Cancer (IARC), there were approximately 2.5 million new cases and around 1.8 million deaths attributed to lung cancer in 2022, imposing an enormous disease burden on society. The high mortality rate of lung cancer is closely associated with its insidious early symptoms, as many patients are often diagnosed at advanced stages. This not only increases the difficulty of treatment but also incurs substantial economic losses. Treatment approaches for lung cancer encompass surgery, radiotherapy, chemotherapy, targeted drug therapy, and immunotherapy. Among these, immunotherapy has emerged as the most groundbreaking research direction in the current field of lung cancer treatment due to its unique anti-tumor mechanisms and remarkable clinical benefits. In contrast to traditional lung cancer treatment modalities such as radiotherapy and chemotherapy, immunotherapy works by activating or enhancing the patient’s own immune system to recognize and eliminate tumor cells, offering advantages such as more durable therapeutic effects and relatively fewer toxic side effects. The main approaches to lung cancer immunotherapy include immune checkpoint inhibitors, tumor-specific antigen-targeted therapy, adoptive cell therapy, cancer vaccines, and oncolytic virus therapy. Among them, immune checkpoint inhibitors and tumor-specific antigen-targeted therapy have received approval from the U.S. Food and Drug Administration (FDA) for clinical use in lung cancer, significantly improving the prognosis of patients with advanced non-small cell lung cancer. Although other types of immunotherapies are still in the clinical trial phase, they also demonstrate tremendous potential in enhancing treatment precision, among other aspects. This article systematically reviews the latest research progress in the field of lung cancer immunotherapy, covering the development of novel immune checkpoint molecules, optimization of treatment strategies, exploration of biomarkers, and recently conducted clinical trials. Additionally, it discusses the challenges facing lung cancer immunotherapy and proposes future research directions, including the development of next-generation immunotherapeutic drugs, exploration of more effective combination treatment regimens, and the establishment of a precise efficacy prediction system. The aim is to provide a reference for the further advancement of this field.