Recent studies have identified that metabolic reprogramming in lung adenocarcinoma cells, particularly lactate metabolism disorders, plays a crucial role in tumor development and immune therapy response. The accumulation of lactic acid not only provides energy support for the proliferation of tumor cells but also affects the function of immune cells by changing the tumor microenvironment, thereby promoting immune escape. Immunotherapy, especially the application of immune checkpoint inhibitors, has become an important strategy for treating lung adenocarcinoma. However, lactate metabolism disorders might affect the efficacy of immunotherapy, leading to resistance in some patients. Therefore, a thorough understanding of the mechanisms of lactic acid metabolism in lung adenocarcinoma and its impact on the response to immunotherapy is essential for developing new therapeutic strategies and improving the efficacy of immunotherapy. This review summarizes the role of lactate metabolism disorders in the development and immunotherapy of lung adenocarcinoma, discusses the potential role of lactic acid metabolism-related genes and pathways in lung adenocarcinoma, and explores the progress in therapeutic strategies targeting lactic acid metabolism regulation. This work aims to provide new insights for the treatment of lung adenocarcinoma.